Like, if you're in a chess midgame, there might still 6 major pieces and 4 or 6 minor pieces and tons of pawns on the board. It's tricky to calculate far into the future. At each node, there's easily dozens of possible moves, and 4-8 viable or not-horrible ones. That's becoming a lot of possibilities to consider very quickly.
In an endgame, there's like, 2 kings, 2 pieces and 4 pawns or a similar constellation. There's 6 possible moves, 3 of them immediately lose and 3 are worth thinking about. 2 of them probably only have one possible answer. Suddenly even an utter beginner like me can calculate 4-8 moves. A master-level player probably knows the endgame entirely, or can see 10 - 20 moves into it easily, because the branching factor is a lot lower now.
Like, if you're in a chess midgame, there might still 6 major pieces and 4 or 6 minor pieces and tons of pawns on the board. It's tricky to calculate far into the future. At each node, there's easily dozens of possible moves, and 4-8 viable or not-horrible ones. That's becoming a lot of possibilities to consider very quickly.
In an endgame, there's like, 2 kings, 2 pieces and 4 pawns or a similar constellation. There's 6 possible moves, 3 of them immediately lose and 3 are worth thinking about. 2 of them probably only have one possible answer. Suddenly even an utter beginner like me can calculate 4-8 moves. A master-level player probably knows the endgame entirely, or can see 10 - 20 moves into it easily, because the branching factor is a lot lower now.