 The 
  Greatest Chess Player of All Time – Part III
The 
  Greatest Chess Player of All Time – Part III
By Jeff Sonas
This is the third installment in a four-part series where I am using various 
  statistical techniques, applied to my brand-new Chessmetrics 
  data, to explore the following question: 
Was Garry Kasparov the most dominant chess player of all time? If not, 
  who was?
In Part I we saw that Emanuel Lasker spent the longest amount of 
  time at the top of the rating list in chess history, as well as the longest 
  amount of time as world champion (unless it was Steinitz). We saw that Wilhelm 
  Steinitz and Bobby Fischer had the largest rating gaps compared to the rest 
  of the world. And then in Part II we saw that Bobby Fischer had the 
  highest rating of all time, and that the two greatest single-event performance 
  ratings of all time were achieved by Anatoly Karpov (best tournament performance 
  ever, at Linares 1994) and Bobby Fischer (best match performance, in Fischer-Larsen 
  match 1971). Where, then, is the justification for claiming that Garry Kasparov 
  might be the most dominant player of all time? 
Despite the impressive accomplishment of Karpov at Linares 1994, it is nevertheless 
  very clear that Garry Kasparov had the most impressive tournament career of 
  any player in chess history. You may have noticed from the final graph in Part 
  II that although Karpov did have the best-ever single tournament performance, 
  it was Kasparov who had five of the top ten of all time, and the story doesn't 
  change much as you run further down the list. For instance, out of the top 
  fifty tournament performance ratings of all time, Kasparov had seventeen of 
  them, with nobody else having more than six:

Despite his fifteen-year run as world champion, with many successful title 
  defenses, Kasparov was significantly more successful in tournaments than in 
  matches. Over the course of his career, he was probably about 40-45 points 
  stronger in tournaments than in matches. For instance, he actually lost rating 
  points over the course of his career in match play. Based upon Kasparov's ratings, 
  and the ratings of his opponents, Kasparov could have been expected to score 
  58% in his matches and he actually scored 57%. On the other hand, despite his 
  high rating, Kasparov gained rating points in three-fourths of the tournaments 
  that he played in, averaging a 69% score rather than the 66% score that his 
  rating would have predicted. This pattern held true even more strongly if you 
  only consider events where his average opponents' rating was 2700+.
As impressive as that above list is for Kasparov, it is important to recognize 
  the context within which these accomplishments occurred. It has been far easier 
  to play in a large number of tournaments in recent years than in the first 
  half of the twentieth century, for instance, with its wartimes and inferior 
  travel opportunities. Nevertheless, the above list is hardly skewed towards 
  recent years if you look at the remaining 33 tournament performances of 2820+. 
That's about as far as I can go with single-event performance ratings. However, 
  there are certainly other ways to measure tournament success. Rather than performance 
  ratings or rating point gains, a more tangible measure would be to look at 
  actual first-place finishes in top tournaments. And as you might expect, Kasparov 
  is at the top of the list however you look at it. 
I mentioned in Part I that I had invented a new way to calculate the "category" 
  of historical tournaments. I have written a lot about this topic in the past, 
  although it was a few years ago. In mid-2000 I was commissioned by KasparovChess.com 
  to write an article somewhat similar to this one, in which I tried to place 
  Kasparov's 1999-2000 tournament success in its proper historical context. In 
  order to compare tournament successes across history, there needs to be a way 
  to make valid comparisons. And the traditional measure of tournament strength, 
  the "category", is going to show a bias towards recent years, partially 
  because of FIDE rating inflation but even more so because of the quantity of 
  highly rated players these days. It is relatively easy to assemble a tournament 
  field with a high average rating, just because there are so many players to 
  choose from. As an example, 28 of the top 30 category tournaments (using Chessmetrics 
  ratings) occurred within the past twenty years. The only exceptions were the 
  super-elite tournament held in St. Petersburg 1895 and the World Championship 
  tournament of 1948. 
The approach that I used in that article five years ago, building upon an 
  original suggestion from Kasparov to use historical top-ten lists rather than 
  ratings, still seems like a sound one, so I am still using it with my new data. 
  My idea is to assign points to each tournament based on the participation of 
  the top-ranked player in the world (worth four points), the #2 player (worth 
  four points), the #3 or #4 player (worth three points each), the #5 or #6 player 
  (worth two points each), and/or the #7 through #10 players (worth one point 
  each). The overall number of points for the tournament should be roughly comparable 
  to the traditional "Category" of the tournament. I call this classification 
  the "class" of a tournament. There is lots more about this on my 
  Chessmetrics site, including historical rankings of the highest-class tournaments. 
  One of the things I show is that the "strongest" tournaments (based 
  on "class") are distributed much more evenly across time, rather 
  than the highest category listing, where the top-30 list of tournaments is 
  still more than 90% made up of tournaments from the past twenty years.
It is a historical curiosity that there has never been a tournament that included 
  all of the top ten players in the world, other than the famous 1970 "USSR 
  vs. The Rest of the World" team event (which really shouldn't count as 
  a tournament). In fact, there has never even been a tournament with the top 
  nine players from the rating list. There have, however, been six tournaments 
  in chess history that included the top eight from the rating list. Two of them 
  (Vienna 1882 and Linares 1993) also included the #10 player and so they share 
  the distinction of being the highest-class tournaments ever (Class 21). The 
  other four tournaments were missing both the #9 and #10 players from the rating 
  list, and so they count as Class 20. Those tournaments were Nottingham 1936, 
  AVRO 1938, Linares 1992, and Corus 2001 (Wijk aan Zee).
I'm amazed that I never noticed this until a few days ago, but it turns out 
  that only one player in chess history has ever won clear first place in a tournament 
  that included the top eight players in the world (i.e., one of those six tournaments 
  I just listed). Guess who is the one player? Garry Kasparov actually achieved 
  this unique feat three different times: twice at Linares and once at Wijk aan 
  Zee. All three of the other tournaments ended with a tie for first place.
Even if you get slightly less exclusive, and go down to the tournaments that 
  included all of the top five players in the world, the list is still dominated 
  by Kasparov. Only five players have ever won clear first place in such a tournament. 
  Emanuel Lasker accomplished it twice: Nuremberg 1896 and St. Petersburg 1914, 
  and three others managed it once (Johannes Zukertort at London 1883, Viswanathan 
  Anand at Reggio Emilia 1991, and of course Anatoly Karpov at Linares 1994). 
  Garry Kasparov, on the other hand, did this more times than everyone else combined, 
  a total of six times (including the three already mentioned, plus Belfort 1988, 
  Las Palmas 1996, and Wijk aan Zee 1999). Just for comparison, Bobby Fischer 
  only played one tournament in his entire life that even had the top three players 
  in the world: Bled/Zagreb/Belgrade 1959, where he finished fifth.
So I think it is indisputable that Kasparov had the most dominant tournament 
  career of anyone in chess history. Nobody else is even close. And in match 
  play, he held the world title for a very long stretch, and in fact never lost 
  a match to any human until the 2000 match against Kramnik where he lost a grand 
  total of two games. Thus it will come as little surprise that since 1985 Kasparov 
  was ranked first for an extremely long stretch.
My Chessmetrics ratings are calculated at the start of each month, using all 
  known game results at that point. Thus players' ratings are actually recalculated 
  during any events that span across multiple months. The first world championship 
  match between Karpov and Kasparov certainly qualifies as a "multiple-month 
  event". Kasparov began the match in September of 1984 with a 34-point 
  rating advantage over Karpov. That rating lead quickly dwindled after Karpov's 
  superlative start to the match, and by game #20 Karpov had retaken the #1 spot. 
  It was not until February of 1985, after winning game #47 of the same match, 
  that Kasparov finally regained the #1 spot, which he then held for almost twenty 
  straight years. This put Kasparov firmly at the top of the next measurement: 
  consecutive months as #1 on the rating list.

Perhaps even more impressive is the firmness with which Kasparov held onto 
  his #1 spot. For a stretch of 18.5 years, not a single other player even came 
  within 10 rating points of Kasparov on any of the monthly lists. Nobody else 
  in chess history has come remotely close to having such a stretch of dominance 
  like that, with Lasker managing 8.8 years, and Karpov 7.8 years, before anyone 
  came within 10 points of them. 
Kasparov finally fell out of the #1 spot on my monthly Chessmetrics rating 
  lists on November 1st, 2004, where the combination of Kasparov's poor performance 
  at the European Cup in October, and Anand's excellent score at the Calvià Olympiad 
  in October, finally lifted Anand into the #1 spot, ending one of the most impressive 
  streaks in chess history. This means Kasparov was actually not the favorite 
  at Linares 2005, since Anand was still ranked #1. It was the first time in 
  24 years that Kasparov did not go into an event as the Chessmetrics rating 
  favorite (going all the way back to Moscow 1981, where the 18-year old Kasparov 
  shared second place behind world champion Karpov, ranked #1 in the world).
My original plan was to stop my analysis, and my series of articles, at this 
  point. I was going to tell you that I had done the best I could, to present 
  these various explorations into the question of who was the most dominant player 
  of all time, and that it was up to you to pick which factor(s) you consider 
  the most relevant. However, a few days before writing this I hit upon another 
  avenue of analysis that I think is really interesting and exciting, and certainly 
  sheds some additional light on the question of who was most "dominant". 
  So instead of a mere three-part article, you're getting a bonus Part IV in 
  a few more days. Hopefully it will be worth the wait...