Yes I think in 1950 or so, Claude Shannon wrote a… an essay about how to make a machine to play chess. And in retrospect, it’s quite obvious what you have to do. You have to generate possible moves and you have to decide which of two moves is better, but you can’t decide that easily except to see what other moves… subsequent moves will result… could result from it. And this was a beautiful paper describing exactly how to make such a machine. There was in fact a similar essay, which hadn’t been widely published, by Alan Turing, the… the scientist in England who also made major discoveries about the foundations of computation. And… I don't know what to say. Computers were still too slow at the time that Shannon wrote this paper to make a chess playing machine but which – now we’re talking about the 1950s – but by 1960 the computers were fast enough and we… we and other people wrote computer programs that did more or less what Shannon had described. And we had the first… the first chess playing machine – I think – was made by Allen Newell and Herbert Simon. And the computer was still too small for a whole chessboard, so it played a sort of… miniature kind of chess on a 6x6 board instead of an 8x8 board. And it beat a secretary who had been taught the rules of chess in the hour previous to this match. So, it was the first machine victory, but I don't think anyone took it very seriously. And then, a couple of years later, John McCarthy invented a strategy which is – for various reasons – is called alpha beta. Which makes the classical chess machine much more efficient and using this trick, by 1960 the simulated chess machines were starting to beat really good players, here and there and... no machine became chess champion of the world until the 1990s, but in the 1960s a… program to play checkers beat the state champion of checkers of Connecticut, a… a large state nearby Massachusetts here. And that was a notable event because no machine had beat a champion player of… at anything before that time.