Post a reply

Re: Rankings revisit - a trip through history

Postby D4P

I don't know how ELO rankings work, but they seem to be created and favored by intelligent people, so I'm inclined to be on board with them.

I also wonder whether a golf-style ranking system might work for snooker. All sanctioned professional golf tournaments throughout the world are assigned a certain number of ranking points, based on the quality of the field and prestige of event. Then, each player receives a subset of those points based on how high they finished in the event. Their world ranking is equal to their total number of points received divided by the number of events they played in, which yields a single number that represents the average number of points they earn in a tournament. Points are weighted such that more recent events count more than less recent events, and a given event's weight declines over time to the point that it drops off completely after (I think?) 2 years.

In snooker, each event could be assigned a certain number of points based on strength of field, prestige of event, etc., and then players could receive a subset of those points based on how far they make it into the event. (There might also be a way to adjust for the quality of opponents faced, such that you get more points for beating top players than for beating numpties, other things being equal). Then, your ranking would be an average of how many points you received per tournament, with the top players having a ranking that might be (for example) roughly the equivalent of making it to the quarterfinals of the top events on average. In golf, the current #1 player's ranking is roughly equivalent to finishing around 10th place in every single prestigious tournament.

One thing that wouldn't work so well in snooker with this kind of ranking system is that, unless I'm mistaken, all players start at zero, and then the rankings are adjusted based on performance. It wouldn't make sense in snooker to all of a sudden start the next event with all 128 players starting with no ranking whatsoever...
Last edited by D4P on 10 Oct 2020, edited 1 time in total.

Re: Rankings revisit - a trip through history

Postby chengdufan

Aside from the rankings debate, I would like to see those who qualify as professionals employed as they would be in any other commercial organisation: given a contract, paid a fixed salary and given expenses for travelling for work. Any prize money they earn would be on top of these basics. If you are in the top 64 at the end of your initial 2 year contract, you get a 1-year extension. If you are not in the top 64 (or another agreed upon level), your contract doesn't get renewed.

Re: Rankings revisit - a trip through history

Postby D4P

chengdufan wrote:Aside from the rankings debate, I would like to see those who qualify as professionals employed as they would be in any other commercial organisation: given a contract, paid a fixed salary and given expenses for travelling for work. Any prize money they earn would be on top of these basics. If you are in the top 64 at the end of your initial 2 year contract, you get a 1-year extension. If you are not in the top 64 (or another agreed upon level), your contract doesn't get renewed.


Sounds too socialistic for Hearn. He prefers dog-eat-dog, every man for himself, winner-takes-all.

Re: Rankings revisit - a trip through history

Postby chengdufan

The 1981 World Championship is complete.

https://en.wikipedia.org/wiki/1981_Worl ... ampionship

23 year-old Steve Davis won his first World title, beating Doug Mountjoy, who was to turn 40 in a couple of months' time, 18-12 in the final.
There is no change in the overall make-up of my top-16 following this event, though Steve moves up from 5th to 1st, and Doug jumps from 14th to 3rd.

There weren't many new players this year, but we do see the introduction of Jimmy White (who lost to Steve Davis in the last 24 (What a draw for a first round!!)) and Tony Knowles.

Here are the rankings:
1 Steve Davis 10799
2 Cliff Thorburn 7777
3 Doug Mountjoy 7487
4 Alex Higgins 6041
5 Kirk Stevens 6007
6 David Taylor 5266
7 Ray Reardon 5099
8 Terry Griffiths 4438
9 Dennis Taylor 4161
10 Bill Werbeniuk 4109
11 Tony Meo 3717
12 John Virgo 3214
13 Eddie Charlton 2950
14 Willie Thorne 2905
15 Jim Wych 2745
16 Ray Edmonds 2525
17 John Spencer 2110
18 Cliff Wilson 2092
19 John Dunning 1932
20 Rex Williams 1789
21 Jimmy White 1624
22 Tony Knowles 1468
23 Graham Miles 1370
24 Eddie Sinclair 1312
25 Dave Martin 1224
26 Joe Johnson 1207
27 Mike Hallett 1204
28 Jim Meadowcroft 1152
29 Fred Davis 846
30 Perrie Mans 828
31 Sid Hood 817
32 David Greaves 789
33 Paddy Morgan 746
34 Patsy Fagan 712
35 Jackie Rea 631
36 Pat Houlihan 626
37 Frank Jonik 544
38 Roy Andrewartha 520
39 Mario Morra 490
40 Roy Amdor 446
41 Mark Wildman 414
42 Bernie Mikkelsen 402
43 Bernard Bennett 379
44 John Pulman 352
45 Maurice Parkin 318
46 Derek Mienie 273
47 Kevin Robitaille 204
48 John Bear 180
49 Ian Anderson 158
50 Paul Thornley 156
51 Jimmy van Rensberg 134
52 Chris Ross 117
53 John Barrie 85
54 Kingsley Kennerley 72
55 Jim Charlton 51
Last edited by chengdufan on 11 Oct 2020, edited 1 time in total.

Re: Rankings revisit - a trip through history

Postby Iranu

chengdufan wrote:
Iranu wrote:Understandable maybe but calculable? I’m not so sure. The vast majority of fans aren’t going to be combing through the rankings looking at all the permutations and working out which players can get up to/fall down to where. Particularly when this info is readily available with online and during TV coverage.

Hell, I’m a diehard snooker fan and I get all my ranking info from TV coverage on here. I’d never be able to tell you who can get into the top 16 at any given time. At least not without paraphrasing a post from Wild or someone from a week earlier!

I don’t really know anything about Elo specifically but I think 99% of fans simply trust the existing and predicted rankings as they are given and I’m sure this wouldn’t be any different.

Fair enough!

I could be wrong of course! But I think people will quickly adapt and take the rankings at face value. When the money rankings came in, there was ultimately no upheaval because at the end of the day they were what they were. The biggest difference was how frequently the rankings changed compared to the two year system.

Re: Rankings revisit - a trip through history

Postby chengdufan

1982!

https://en.wikipedia.org/wiki/1982_Worl ... ampionship

Alex Higgins beat Ray Reardon 18-15 in the final, clinching the match with a 135 clearance. Despite his win, he only moves from 4th to 2nd in the rankings, with runner-up Reardon moving ahead of him from 7th back to number 1.

It was another expanded field this year, with 22 new players, including Silvino Francisco and Dean Reynolds, who had deep runs.
Francisco and Reynolds go straight into the top 16, and are joined by Jimmy White (up from 21st to 3rd). and Tony Knowles (22 to 5). John Spencer and Patsy Fagan also return to the top 16.
David Taylor, Dennis Taylor, John Virgo, Jim Wych and Ray Edmonds drop out of the 16, along with Terry Griffiths (down from 8 to 26) who lost to Willie Thorne in the first round this year.

Here are the new rankings, with a couple of Snooker Island favourites at 60 and 63:

1 Ray Reardon 7704
2 Alex Higgins 7216
3 Jimmy White 5972
4 Doug Mountjoy 4794
5 Tony Knowles 4254
6 Eddie Charlton 4060
7 Willie Thorne 3912
8 Steve Davis 3718
9 Silvino Francisco 3144
10 Kirk Stevens 3024
11 Bill Werbeniuk 2164
12 Dean Reynolds 2132
13 Tony Meo 2106
14 Patsy Fagan 2072
15 Cliff Thorburn 1792
16 John Spencer 1668
17 David Taylor 1600
18 Cliff Wilson 1508
19 Dennis Taylor 1502
20 Graham Miles 1496
21 John Bear 1464
22 John Virgo 1444
23 John Dunning 1372
24 Dave Martin 1332
25 Perrie Mans 1300
26 Terry Griffiths 1276
27 Jim Donnelly 1264
28 Rex Williams 1216
29 Jim Meadowcroft 1164
30 Mike Hallett 1122
31 Eddie Sinclair 1084
32 Joe Johnson 1056
33 Ray Edmonds 1052
34 Mario Morra 874
35 Jack Fitzmaurice 776
36 Mike Watterson 732
37 Paddy Morgan 732
38 Mark Wildman 678
39 Doug French 656
40 Dennis Hughes 640
41 Paul Medati 628
42 Murdo MacLeod 576
43 Pat Houlihan 524
44 Fred Davis 518
45 Ian Black 472
46 Colin Roscoe 436
47 Billy Kelly 416
48 David Greaves 402
49 Eugene Hughes 364
50 Maurice Parkin 360
51 Bernie Mikkelsen 336
52 Geoff Foulds 320
53 Eddie McLaughlin 320
54 Matt Gibson 320
55 Jim Wych 276
56 Bernard Bennett 276
57 Ian Anderson 272
58 Bert Demarco 240
59 Vic Harris 208
60 Dessie Sheehan 200
61 Tommy Murphy 200
62 Frank Jonik 186
63 Clive Everton 160
64 John Phillips 120
65 Sid Hood 104
66 Roy Andrewartha 104
67 John Pulman 56

Re: Rankings revisit - a trip through history

Postby chengdufan

The 1982-83 season sees 3 ranking events, The International Open, The Professional Players Tournament, and The World Championship. The IO and PPT were played in October 1982.

So first to the 1982 International Open.
https://en.wikipedia.org/wiki/1982_International_Open

There were a few surprises, including Cliff Wilson beating Doug Mountjoy and Jimmy White.
And Tony Knowles beat David Taylor in the final 9-6.

In the rankings following the tournament, Reardon and Higgins retain the top two spots, and Knowles moves up from 5th to 3rd.
David Taylor, John Virgo, Cliff Wilson and Dennis Taylor enter the top 16, in place of Tony Meo, John Spencer, Cliff Thorburn and Patsy Fagan.
Further down the rankings, there are big leaps for Eddie Sinclair (31 to 22), Billy Kelly (47th to 36th), Eugene Hughes (49th to 37th) and Jim Wych (55th to 43rd).
Les Dodd enters the rankings at number 47.
Overseas players Silvino Francisco (ranked 9th) and John Bear (ranked 21st) did not play.

1 Ray Reardon 8160
2 Alex Higgins 7648
3 Tony Knowles 7622
4 Jimmy White 6384
5 Doug Mountjoy 5018
6 Steve Davis 4638
7 Kirk Stevens 4440
8 David Taylor 4368
9 Eddie Charlton 4284
10 Willie Thorne 4116
11 John Virgo 3456
12 Silvino Francisco 3144
13 Cliff Wilson 3144
14 Dean Reynolds 2808
15 Bill Werbeniuk 2596
16 Dennis Taylor 2422
17 Terry Griffiths 2416
18 Tony Meo 2262
19 John Spencer 2244
20 Cliff Thorburn 2224
21 Patsy Fagan 2120
22 Eddie Sinclair 1808
23 Rex Williams 1784
24 Perrie Mans 1732
25 Ray Edmonds 1664
26 Graham Miles 1544
27 Dave Martin 1524
28 Jim Meadowcroft 1512
29 Mike Watterson 1492
30 John Bear 1464
31 John Dunning 1452
32 Mike Hallett 1426
33 Jim Donnelly 1384
34 Mark Wildman 1266
35 Joe Johnson 1264
36 Billy Kelly 1220
37 Eugene Hughes 1188
38 Jack Fitzmaurice 1128
39 Mario Morra 1082
40 Doug French 864
41 Paul Medati 784
42 Paddy Morgan 732
43 Jim Wych 728
44 Colin Roscoe 704
45 Fred Davis 662
46 Dennis Hughes 640
47 Les Dodd 624
48 Murdo MacLeod 616
49 Pat Houlihan 604
50 Ian Black 592
51 Eddie McLaughlin 580
52 Vic Harris 520
53 Mick Fisher 512
54 Bernard Bennett 484
55 Geoff Foulds 480
56 Maurice Parkin 440
57 David Greaves 402
58 Ian Anderson 376
59 Matt Gibson 360
60 Bernie Mikkelsen 336
61 Bert Demarco 320
62 Dessie Sheehan 320
63 Ian Williamson 316
64 Frank Jonik 290
65 George Scott 276
66 Tommy Murphy 240
67 Clive Everton 200
68 Bob Harris 160
69 John Phillips 120
70 Sid Hood 104
71 Roy Andrewartha 104
72 Marcus Owen 80
73 John Pulman 56
74 Graham Cripsey 40

Re: Rankings revisit - a trip through history

Postby chengdufan

1982 Professional Players Tournament
https://en.wikipedia.org/wiki/1982_Prof ... Tournament

50 year-old world number 1 Ray Reardon won this event. He beat Jimmy White, who was 30 years his junior, 10-5 in the final.

Interestingly, the top 2 in the rankings met in the last 32, with Reardon beating Higgins 5-2. The score is recorded as 4-2 on Wiki, but I trust Cuetracker's 5-2 more, especially as it has the frame scores of the match listed.

Steve Davis was the only really notable absentee from the event. Does anyone know why he didn't play?

So in the rankings, Jimmy moves up from 4th to 2nd. S Davis drops to 17th, and Terry Griffiths re-enters the top 16 in his place.
Joe Johnson had a good run to the quarter-finals, including a 5-1 win over number 7 Kirk Stevens, and moves up from 35th to 21st.

1 Ray Reardon 11256
2 Jimmy White 8730
3 Alex Higgins 7920
4 Tony Knowles 7735
5 Eddie Charlton 6282
6 John Virgo 5082
7 Kirk Stevens 4344
8 Willie Thorne 4208
9 David Taylor 4096
10 Doug Mountjoy 3625
11 Cliff Wilson 3568
12 Dean Reynolds 3552
13 Bill Werbeniuk 3190
14 Silvino Francisco 3144
15 Terry Griffiths 3046
16 Dennis Taylor 2863
17 Steve Davis 2807
18 John Spencer 2442
19 Tony Meo 2365
20 Eddie Sinclair 2354
21 Joe Johnson 2280
22 Patsy Fagan 2102
23 Cliff Thorburn 2080
24 Perrie Mans 2074
25 Mark Wildman 2059
26 Rex Williams 1890
27 Mike Watterson 1812
28 Jim Meadowcroft 1776
29 Dave Martin 1594
30 Jim Donnelly 1592
31 Mike Hallett 1583
32 Ray Edmonds 1554
33 John Bear 1464
34 Graham Miles 1372
35 Eugene Hughes 1356
36 Jack Fitzmaurice 1336
37 John Dunning 1258
38 Billy Kelly 1220
39 Doug French 1212
40 Murdo MacLeod 1196
41 Mario Morra 1133
42 Pat Houlihan 1004
43 Jim Wych 894
44 Paul Medati 836
45 Paddy Morgan 832
46 Dennis Hughes 776
47 Colin Roscoe 756
48 Ian Black 728
49 Frank Jonik 705
50 Fred Davis 703
51 Eddie McLaughlin 684
52 Vic Harris 676
53 Les Dodd 624
54 Bernard Bennett 614
55 Clive Everton 580
56 Geoff Foulds 532
57 Bert Demarco 524
58 Mick Fisher 512
59 Matt Gibson 464
60 Ian Anderson 424
61 Maurice Parkin 380
62 Dessie Sheehan 360
63 Ian Williamson 316
64 Bernie Mikkelsen 288
65 Marcus Owen 288
66 George Scott 276
67 David Greaves 241
68 Tommy Murphy 240
69 Bob Harris 160
70 Jackie Rea 136
71 John Phillips 120
72 Sid Hood 52
73 Roy Andrewartha 52
74 Graham Cripsey 40
75 John Pulman 28

Re: Rankings revisit - a trip through history

Postby chengdufan

To keep this thread from getting too annoying, I'm planning from now on just to post the rankings for the last two tournaments of each season, so we can see the rankings going into the World Championship, and the end of season rankings.

Once we're at a stage where players have played in at least 10 tournaments which contribute to the rankings, I'm also planning to do some analysis of my rankings against the real rankings of the time.

Re: Rankings revisit - a trip through history

Postby chengdufan

So the 1983 World Championship is next.
https://en.wikipedia.org/wiki/1983_Worl ... ampionship

Steve Davis romped through the field and thrashed Cliff Thorburn 18-6 in the final.
The final wasn't a surprise pairing at the time, with Thorburn seeded 3 and Davis seeded 4. However, with my rankings they were at 23rd and 17th respectively going in to the tournament.
Does that mean my rankings are rubbish? The short answer is: yes! In the case of Steve Davis, he is certainly ranked artificially lowly by me because he didn't enter one of the only other two ranking events this season. But let's not forget that he lost 10-1 to Knowles too in the previous year's Championship. He remained 4th in the real rankings because of his win in '81, but I don't think that means the real rankings were any better than mine. It seems it was more luck than judgment on the part of the real ranking system.

Let's look at Thorburn's recent results to see why he's at 23 on my list.
In the 1981 WC, he reached the semi-finals.
In the 1982 WC, he lost in the first round to Jimmy White.
In the 2 earlier 1982-83 ranking events, he beat George Scott, Paul Medati and Clive Everton before losing in the last 16 of each event.
You certainly wouldn't think he'd be the third seed with those results. However, perhaps 23 is too low.

The real problem is the infrequency of the ranking events. That's something I think will change as we get to the mid 80s and beyond.

Re: Rankings revisit - a trip through history

Postby chengdufan

So, at the end of the '83 World Championship, Tony Knowles tops the rankings after his stellar run to the semi-finals, where he lost in the deciding frame to Thorburn. Reardon drops to no.2 and Jimmy is down to 5.

Davis, Thorburn and Meo re-enter the top 16, at 4, 7 and 9 respectively, while Griffiths, Mountjoy and Dennis Taylor lose their top 16 status.

John Campbell is the highest new entrant on the list at no.42

1 Tony Knowles 10322
2 Ray Reardon 9622
3 Alex Higgins 9274
4 Steve Davis 7248
5 Jimmy White 6691
6 Eddie Charlton 6569
7 Cliff Thorburn 6028
8 Kirk Stevens 5556
9 Tony Meo 5225
10 Willie Thorne 4549
11 Bill Werbeniuk 4541
12 John Virgo 4475
13 David Taylor 3949
14 Dean Reynolds 3592
15 Cliff Wilson 3475
16 Silvino Francisco 3458
17 Terry Griffiths 3391
18 Doug Mountjoy 3064
19 John Spencer 3046
20 Eugene Hughes 2765
21 Joe Johnson 2560
22 Dennis Taylor 2523
23 Mark Wildman 2458
24 Eddie Sinclair 2433
25 Rex Williams 2359
26 Mike Hallett 2335
27 Perrie Mans 2308
28 Jim Meadowcroft 2280
29 Dave Martin 2134
30 Patsy Fagan 1823
31 Jim Donnelly 1698
32 Ray Edmonds 1695
33 Murdo MacLeod 1669
34 Billy Kelly 1663
35 Graham Miles 1658
36 Ian Black 1610
37 Mike Watterson 1599
38 Mick Fisher 1568
39 Les Dodd 1544
40 John Bear 1378
41 Eddie McLaughlin 1353
42 John Campbell 1336
43 Jack Fitzmaurice 1282
44 Tommy Murphy 1260
45 Paddy Morgan 1242
46 Doug French 1229
47 Paul Medati 1227
48 Mario Morra 1146
49 Pat Houlihan 1113
50 Ian Williamson 1077
51 Geoff Foulds 1015
52 Graham Cripsey 750
53 Warren King 720
54 Frank Jonik 679
55 John Dunning 678
56 Colin Roscoe 671
57 Dennis Hughes 662
58 Jim Wych 639
59 Matt Gibson 588
60 Bernard Bennett 558
61 Bert Demarco 553
62 Fred Davis 532
63 Ian Anderson 531
64 Dessie Sheehan 510
65 Vic Harris 507
66 Clive Everton 503
67 Bob Harris 484
68 Marcus Owen 416
69 Roy Andrewartha 364
70 Pascal Burke 360
71 David Greaves 340
72 Maurice Parkin 292
73 George Scott 207
74 Bernie Mikkelsen 180
75 Jackie Rea 102
76 John Phillips 90

Re: Rankings revisit - a trip through history

Postby D4P

chengdufan wrote:Does that mean my rankings are rubbish? The short answer is: yes! In the case of Steve Davis, he is certainly ranked artificially lowly by me because he didn't enter one of the only other two ranking events this season.


Does this imply that your ranking system is based on adding up a player's results across tournaments, rather than taking some kind of average...?

Re: Rankings revisit - a trip through history

Postby SnookerEd25

Great stuff ChengduFan, this continues to be far & away my favourite active thread at present.

Just a note regarding 1981 though, Doug Mountjoy was born in 1942, so he hadn’t even turned 40 yet - let alone the 50 you had him knocking on the door of!

Keep up the good work! :clap:

Re: Rankings revisit - a trip through history

Postby chengdufan

SnookerEd25 wrote:Great stuff ChengduFan, this continues to be far & away my favourite active thread at present.

Just a note regarding 1981 though, Doug Mountjoy was born in 1942, so he hadn’t even turned 40 yet - let alone the 50 you had him knocking on the door of!

Keep up the good work! :clap:

Haha!! Good spot.

Apologies to Doug :dizzy:

Re: Rankings revisit - a trip through history

Postby chengdufan

D4P wrote:
chengdufan wrote:Does that mean my rankings are rubbish? The short answer is: yes! In the case of Steve Davis, he is certainly ranked artificially lowly by me because he didn't enter one of the only other two ranking events this season.


Does this imply that your ranking system is based on adding up a player's results across tournaments, rather than taking some kind of average...?

Yes, every frame you win within a two year period counts, with weightings for round, opponent, recency, and whether it's a match or tournament winning frame.

However, Stevie D coming into the 83 WC ranked 17 has got me thinking about making a change.
I'm on the case.

Re: Rankings revisit - a trip through history

Postby chengdufan

So what I'm thinking is this.
If you miss a tournament for some reason, you get 50% of the points you would have received if you had done as well as expected.
So if your rank is x, then we see how many points the xth highest point scorer in the event got, halve it, and award you those points.

Steve Davis was ranked 6th before the event he missed. The 6th highest point scorer in the event was Joe Johnson, who got 288 points in my system.
If I award Steve 144 for that event, he moves up from 17th to 13th.

I like this way of doing it, but the challenge is that I need to know why a player hasn't played. If they have retired, or are an amateur who will only play a ranking event occasionally, I don't think it's worth adding points for them in this way.
For professionals who will play most events subsequently, this works, but how do I know for these past events?

Re: Rankings revisit - a trip through history

Postby chengdufan

I've decided to implement this new system, but only up to a maximum of 3 consecutive ranking events. After you have missed three in a row, the charity ends, and you start to get 0.
Edit: I'm also only going to apply the charity points to players who have played in at least two of the 5 ranking events preceding the first absence.
Last edited by chengdufan on 11 Oct 2020, edited 1 time in total.

Re: Rankings revisit - a trip through history

Postby chengdufan

I've only done 12 events so far, and so can make the necessary adjustments from event two onwards. Don't worry, I won't repost the rankings for the earlier events (unless requested), but will repost the rankings following the 1983 WC

Re: Rankings revisit - a trip through history

Postby Badsnookerplayer

Iranu wrote:
chengdufan wrote:
Iranu wrote:Understandable maybe but calculable? I’m not so sure. The vast majority of fans aren’t going to be combing through the rankings looking at all the permutations and working out which players can get up to/fall down to where. Particularly when this info is readily available with online and during TV coverage.

Hell, I’m a diehard snooker fan and I get all my ranking info from TV coverage on here. I’d never be able to tell you who can get into the top 16 at any given time. At least not without paraphrasing a post from Wild or someone from a week earlier!

I don’t really know anything about Elo specifically but I think 99% of fans simply trust the existing and predicted rankings as they are given and I’m sure this wouldn’t be any different.

Fair enough!

I could be wrong of course! But I think people will quickly adapt and take the rankings at face value. When the money rankings came in, there was ultimately no upheaval because at the end of the day they were what they were. The biggest difference was how frequently the rankings changed compared to the two year system.

:zzz:

Re: Rankings revisit - a trip through history

Postby chengdufan

Thanks to those of you who have expressed encouragement in me continuing with this project, either in this thread or by PM. I'm amazed to hear of the interest in it really. I thought I might just be conversing with myself in this thread!!
I think what this shows is that people do care about the rankings, and recognition that a new system is needed is agreed upon by virtually everybody.

I would like to talk a bit more about my system and how it works here, and why I've chosen this method over others. I'll do this in a new post below. It will probably be lengthy, so feel free to get the zebra out.

Re: Rankings revisit - a trip through history

Postby chengdufan

First of all, I started to think about what a match tells us about a snooker player's ability. I also thought about what makes snooker unique.

Here are some things that came to mind:
- It is much harder to win a frame in the first round against a high seed than against a low-ranked player.
- That's not the full story though. It's easier to win frames in an early round than a later round. You often see a rusty performance early on in a tournament from a high seed. Similarly, lower ranked players sometimes have an exceptional week where they perform above expectations.

So, the rankings need to take into account the level of opponent, but also the round of the competition.

- The more matches that are considered in the rankings, the better.
- However, it seems fair to me to assume that the more recent the match, the more relevant it is to the player's current ability. There are all kinds of reasons why a player's performance level dips and rises. Snooker is not a sport in which we can expect a similar ability to be demonstrated by a player across a number of years, perhaps with a gradual improvement up to a peak, before a gradual decline.

So, we should limit how far back in time we go, but need to weight the rankings to the more recent matches.
Ideally, the points scored by a particular match would gradually depreciate over time until they reach 0. However, partly due to my limited Excel skills and partly because the records of dates of matches on cuetracker don't exist (only tournament dates), I have decided to make it simple. I've gone with a 2 year system. Points from matches within the last 6 months are multiplied by 4, 6-12 months 3, and 12-18 months 2.

- It seems to me that it is generally harder for a player to get over the line than it is to win a normal frame in a match.
- Some high profile examples are Matthew Stevens and John Higgins. Stevens at his best could win frames easily, but getting that winning frame was a struggle. Higgins may have been equally talented in the 00s in terms of winning the bog standard frames, but he never seemed to find it hard to get over the line. This ability, and therefore the ability to win matches, should be recognised in the rankings. I also often see low ranked players get within one frame of winning against a top player before 'bottling' it. So while I don't have empirical evidence to indicate this, my intuition tells me that a weighting for a match-winning frame is needed. I have similarly decided to give even more of a weighting to a tournament winning frame.
- So, now let's consider a situation. You are 4-0 down in a best of 9. It is harder for your opponent to win that 5th frame than the previous 4, so logically it is easier for you to start winning frames. So if you bring it back to 4-4, perhaps the points you score for those 4 frames should be reduced? Well, probably, yes. But just like the gradual depreciation over time, while I would probably factor that in if I were comissioned to create a real ranking system, for my home Excel spreadsheet, it adds an extra level of complexity that I don't need. It is not important enough for me to go to the time and effort to put in.

So, I'm going to stick with the match and tournament winning frames getting a bonus.

- Some players have more opportunity to play than others. Should I therefore give players an average score per match?
- Well, no. With my system, you do get more points the more frames and matches you play. But does this help or hinder the rankings?
- Typically, you get to play more matches because you are winning and are a better player, so your points should increase in this way.
- Similarly, the longer the match format, the harder it is to progress in a tournament. So matches won in the World Championship should count for a lot more than matches won in the Shootout.

Re: Rankings revisit - a trip through history

Postby chengdufan

Let's recap at this point. What is being considered in my ranking system so far?
Quality of opponent
Round of event
Recency
Number of frames in a match
Whether a frame is match or tournament winning

So is it possible to use an existing ranking system that covers all these things? I don't think so, not from my research anyway. I get why people like Elo , but can it apply to snooker when you consider all of the above, I don't think so.

Ok, my rankings consider all of the above, so what are its weaknesses, aside from the 2 items I've described already?
Well, as we've just seen from 1983, the rankings are unfairly skewed if a player misses an event. That has a big impact in these early years when there aren't enough events, but the effect, albeit smaller, will be there to some extent in the future, when Ronnie starts skipping tournaments, and Vafaei has visa troubles. So is there anything I can do to address this?
D4P sensibly mentioned using 'averages'. Now my thinking on this is that it would be great, but... You would need to use averages from every type of frame. At the moment, I have 120 different points possibilities awarded for each frame, based on the factors and weightings mentioned, not including the match/tournament winning bonuses. So to get a sample size large enough for averages to work, you'd probably be looking at at least 10-15 years' worth of results. Not gonna happen. So you either compromise on the above conditions, or drop the 'averages' idea. I'm going to drop averages, I want the conditions I've mentioned under consideration.

So what can be done about skipped tournaments? You get points for every frame played, so in my system, if someone doesn't enter an event, a weaker player will jump above them not because they are a better player, but just because they had the chance to play.
This brings me to the 50% of expected score compromise, as mentioned in previous posts. If the rankings are working, you would expect to get the 'expected score' on average if you played the event an infinite number of times. Sure, sometimes you will lose to 0 in the first round, and other times you will win the thing, but the expected score will be the average. So by giving 50%, you are not rewarded for not playing (which may be out of your control), but the impact on the accuracy of the rankings is reduced significantly.
Think about a comparison of being sick from work. In some places, people get their full salary while on sick leave (a 100% expected score). In other places, you receive a percentage of your salary (similar to my idea here). If you stay off sick for long enough, you will lose your job (in my rankings, this 50% charity ends after 3 events).

Are there any other weaknesses with my system?
The main one I can think of is the allocations and weightings. I know what I want considered, but I have no scientific evidence to determine how to make the weightings. It is purely based on my own intuition and knowledge of snooker.

So, in conclusion, my system is simple enough to use. I can work out all the rankings up to the present day on my own in my spare time (it will probably take me a year or so to get to the present day but I'll get there). I am confident that it will prove to be much more accurate than the real rankings, and I plan to do calculations to compare this, starting from the 1985 British Open. I even think it might work better than Elo. Probably not, because of the limitations I have described, but would be very interested to see comparisons later on, when we get to say 2012-19 when there were lots of tournaments.

I do think a professional could take this idea as a base, put the time and formulae in to increase the accuracy, and come up with a perfect model. But here, it is just me and Excel having a bit of fun :)

Re: Rankings revisit - a trip through history

Postby chengdufan

So I've caught back up to the end of the 1983 WC with the new points added in to compensate for missed events.
Thankfully, not much has changed. The following has:
- Steve Davis gets a few more points, but his rank doesn't change.
- Dean Reynolds loses a few points, but his rank does change.
- Silvino Francisco loses a few points and swaps position with Terry Griffiths (16/17)
- John Bear jumps from 40 to 33.
- There are bits of movements lower down the rankings

Re: Rankings revisit - a trip through history

Postby chengdufan

Here is the draw for the final stages of the 1984 World Championship, with current rankings in brackets :-)

Steve Davis (1) v Warren King (49)
John Spencer (15) v Graham Miles (42)
Terry Griffiths (9) v Paul Mifsud (88)
Bill Werbeniuk (18) v Fred Davis (68)
Alex Higgins (11) v Neal Foulds (70)
Doug Mountjoy (24) v Mike Hallett (16)
Dennis Taylor (28) v Joe Johnson (8)
Tony Knowles (2) v John Parrott (27)
Cliff Thorburn (4) v Mario Morra (29)
John Virgo (22) v Willie Thorne (7)
Jimmy White (13) v Rex Williams (19)
Eddie Charlton (5) v Roy Andrewartha (59)
Kirk Stevens (10) v Eddie Sinclair (31)
David Taylor (20) v Marcel Gauvreau (84)
Tony Meo (3) v Silvino Francisco (17)
Ray Reardon (6) v Jim Wych (65)

Two top sixteen players failed to qualify.
World number 12, Mark Wildman, lost 10-9 to Roy Andrewartha in the final qualifying round.
Number 14, Eugene Hughes, lost to Paul Mifsud 10-5 in the first round of qualifying.

Re: Rankings revisit - a trip through history

Postby The_Abbott

These are a great read and its amazing how many players have got lost in time. I hardly remember some of them yet I was a massive fan in the 80's.

Re: Rankings revisit - a trip through history

Postby chengdufan

chengdufan wrote:Here is the draw for the final stages of the 1984 World Championship, with current rankings in brackets :-)

Steve Davis (1) v Warren King (49)
John Spencer (15) v Graham Miles (42)
Terry Griffiths (9) v Paul Mifsud (88)
Bill Werbeniuk (18) v Fred Davis (68)
Alex Higgins (11) v Neal Foulds (70)
Doug Mountjoy (24) v Mike Hallett (16)
Dennis Taylor (28) v Joe Johnson (8)
Tony Knowles (2) v John Parrott (27)
Cliff Thorburn (4) v Mario Morra (29)
John Virgo (22) v Willie Thorne (7)
Jimmy White (13) v Rex Williams (19)
Eddie Charlton (5) v Roy Andrewartha (59)
Kirk Stevens (10) v Eddie Sinclair (31)
David Taylor (20) v Marcel Gauvreau (84)
Tony Meo (3) v Silvino Francisco (17)
Ray Reardon (6) v Jim Wych (65)

Two top sixteen players failed to qualify.
World number 12, Mark Wildman, lost 10-9 to Roy Andrewartha in the final qualifying round.
Number 14, Eugene Hughes, lost to Paul Mifsud 10-5 in the first round of qualifying.

It's good to see some fresh names at the Crucible this year. 20 year olds John Parrott and Neal Foulds have been causing a bit of a stir on tour. Parrott especially after advancing to the semi-final of the Classic in January, only losing to Steve Davis in a deciding frame.

Paul Mifsud being there is quite a shock. The Maltese player, who will turn 40 soon, has only played one ranking event match so far, also in the recent Classic. He lost that match to World number 77 Tony Jones in the first qualifying round.
Another new face is 28 year old Marcel Gauvreau from Canada. He too hadn't won a ranking match before this WC, having played and lost in the first qualifying round of two events so far.

Re: Rankings revisit - a trip through history

Postby SnookerEd25

The_Abbott wrote:These are a great read and its amazing how many players have got lost in time. I hardly remember some of them yet I was a massive fan in the 80's.


ChengduFan; are you aware that there were a pair of Canadian brothers, both pro’ snooker players - John & Jim Bear? Just checking in case you have taken the results of ‘J. Bear’ to be one player, which may skew your rankings...

Re: Rankings revisit - a trip through history

Postby chengdufan

SnookerEd25 wrote:
The_Abbott wrote:These are a great read and its amazing how many players have got lost in time. I hardly remember some of them yet I was a massive fan in the 80's.


ChengduFan; are you aware that there were a pair of Canadian brothers, both pro’ snooker players - John & Jim Bear? Just checking in case you have taken the results of ‘J. Bear’ to be one player, which may skew your rankings...

Yes, thanks for this. I did know there were these two, but now you mention it, I only recall including one in the rankings so far. I will double check when I get home from work <ok>