A ressource (Nalimov Endgame Tablebases)
It’s simple: Enter the position you want to evaluate, see what ‘the program’ says. If you limit yourself to endgame positions with 6 pieces (and avoid 5+1 situations – but let’s just say these aren’t terribly important in praxis), it has all the answers. Every single one. Chess is basically ‘solved’ for these positions. And now you can look up the answer and get it in no time, at no cost.
To take an example: Imagine a position with a black king on g2, a black queen on f3 vs a white pawn on d5, a white king on d6 and a white queen on a5. Like this:
To people who don’t already know, queen endgames are insanely complicated and this is wildly complex stuff. Many master players would end up drawing this because of imprecise play. In the position above, with white to move he has 23 options – there are 23 moves he can play, 16 queen moves and 7 moves by the king. There is one, and only one, winning move – every single other move will either draw or lose him the game with correct play by black. The winning move is Kc7. There are 52 moves more to go before the win is secured.
This is an extremely cool ressource!