There was an explosion in computer strength about 10 years ago. It was discovered that you could test changes to a program using very fast time controls (e.g. game in 5 seconds). In general the results scale to slower time controls. This enabled programmers to test lots of different evaluation functions and search strategies and figure out the best ones. In effect there was a shift from chess knowledge to statistical rigor. This strategy was extremely effective and raised the strength of chess engines to 3300 ELO, whereas the best humans are “only” 2800 ELO.