The most comprehensive computer analysis of world champions conducted to date puts Cabablanca clearly ahead when evaluating accuracy of play. Opening theory is largely taken out of consideration by starting the analysis after move 12, otherwise modern players would be clearly favored. Murphy is not included int his study, but there have been similar ones that show his level of play was rather subpar compared to most of these guys.
http://www.chessbase.com/news/2006/world_champions2006.pdf
Computer analysis of World Chess Champions
Matej Guid and Ivan Bratko
University of Ljubljana,
Some excerpts:
2 Method
We evaluated fourteen classic version world champions, since the first World
Chess Championship in 1886 to the present. Matches for the title of ”World
Chess Champion”, where they contended for or were defending the title, were
selected for analysis.
Roughly, the basis for evaluation of a human’s play was the difference between
position values resulting from the moves played by the human and the moves
chosen as best by the chess program. This approach can be criticized on the
basis that sometimes there are alternative, equally strong moves, and the choice
between them is the matter of playing style and not merely chess strength. We
will return to this issue later and provide a refinement and a justification for this
approach.
Evaluation of each game started on the 12th move, without the use of an
openings library, of course. This decision was based on the following careful de-
liberation. Not only today’s chess programs poorly evaluate positions in the first
phase of a game, but also analysing games from the start would most likely
favour more recent champions, due to vast progress made in the theory of chess
openings. Starting the analyses on a later move would, on the other hand, discard
too much information. The chess program Crafty [3], which we slightly modi-
fied for the purpose of analyses, was used. Instead of time limit, constant fixed
search depth was applied on every move.
Results
[...]
According to this analysis (Fig. 3), the winner was the third world champion,
Jose Raul Capablanca. We expected positional players to perform better by this
criterion than tactical players. Capablanca is widely renowned to be a pure
positional player. On the other hand Steinitz, who lived in an era of tactical
“Romantic chess”, took clearly last place.
The results of blunder rate measurement are similar (Fig. 4). Notice the
excellent result of Petrosian, who is widely renowned as a player who almost
never blundered. Gary Kasparov describes Capablanca with words “He contrived
to win the most important tournaments and matches, going undefeated for years
(of all the champions he lost the fewest games).” and “his style, one of the purest,
most crystal-clear in the entire history of chess, astonishes one with his logic.
[...]
Another criterion was expected number of best move played providing that
all players dealt with positions with equal difference between the best two moves,
as was described in the previous section. It represents another attempt to bring the champions to a common denominator. Kramnik, Fischer and Alekhine had
the highest percentage of best moves played, but also the above mentioned dif-
ference was high. On the contrary, Capablanca, who was right next regarding
the percentage of best move played, on average dealt with the smallest differ-
ence between the best two moves. The winner by this criterion was once again
Capablanca. He and Kramnik again clearly outperformed the others.
4 Conclusion and future work
We applied the slightly modified chess program Crafty as tool for computer
analysis of games played by world chess champions aiming at an objective com-
parison of chess players of different eras. Generally, the results of our computer
analysis can be nicely interpreted by a chess expert. Some of the results might
appear quite surprising and may thus be considered also as an interesting con-
tribution to the field of chess. Capabalanca’s outstanding score in terms of mean
value loss will probably appear to many as such an interesting finding, although
it probably should not come as a complete surprise. As we did in this study,
this result should be interpreted in the light of the comparatively low complex-
ity of positions in Capablanca’s games which is quite in line with the known
assessments in the chess literature of his style. For example, Kasparov [2] when
commenting Capablanca’s games speculates that Capablanca occasionally did
not even bother to calculate deep tactical variations. The Cuban simply pre-
ferred to play moves that were clear and positionally so strongly justified that
calculation of variations was simply not necessary.
[...]
