Here are the specific mentions of chess:
Studies of chess masters . . . usually find their IQs to be above average, typically in the 115 to 130 range, where some 14 per cent of the population reside - impressive enough, but hardly as rarefied as their achievements and abilities.
So what do elite performers attain through all [their] deliberate practice and sensitive mentoring? What makes a genius? The crème de la crème appear to develop several important cognitive skills. The first, called "chunking", is the ability to group details and concepts into easily remembered patterns. Chess provides the classic illustration. Show a chess master a game in progress for just 5 seconds and they will memorise the board so well that they can recreate most of it - 20 pieces or more - an hour later. A novice will be able to place just four or five pieces.
Yet chess masters don't necessarily have a better memory than novices. Their clustering skills begin and end at the chessboard. Show a master and a novice a random list of 20 digits, and a few minutes later neither will be able to recall more than seven or eight of them in sequence. In a chess game, by contrast, the master sees not the 20 pieces that confront the novice but clusters of pieces, each of which is familiar from experience. Interestingly, the chess master will remember about as many clusters - four or five - as a novice will individual pieces. The better the master, the larger the clusters he'll remember.
- although the whole thing is certainly worth a read.