leavenfish wrote: ↑Wed Sep 11, 2019 5:21 amConceptually I can't wrap my brain around that being so at both blitz and long time controls.
Because no programmer had ever cared about alternative moves in chess positions, they make the engine use 100% of its resources to find the best possible move and play it, and that's it, and they spend 100% of their time improving the engine so that this best move is better, and the rest doesn't matter. MultiPV or the searchmoves feature are almost an after-thought, most engines implement it naively (it was easy for me to suggest a change that improved Stockfish's elo at MultiPV by a significant amount), but most engines don't ever have a way for the engine to show an alternative to what they consider best, and their programmers only care about elo.
That's why when you switch to MultiPV, the engine switches into "dumb mode", it was not designed to analyze more than 1 move at a time, such a thing was never optimized, so you get incredibly poor results. Ironically, switching it on in some positions is the only way for the engine to find some moves, because those are ones it wasn't designed to be good at, because such positions are rare so being good at them doesn't bring the elo points, and all that matters is the elo.
There are notable exceptions, like engines designed to be weakened to provide an interesting opponents for people, and others that allow creating interesting personalities to put flavor in the games. And Komodo MCTS is such a thing, specially designed to be able to provide alternative moves in positions, easily surpassing the performance of stronger engines that weren't designed for this.
Of course if this MCTS system to give the best possible alternative moves was implemented in Stockfish instead of Komodo, we'd be getting much better alternatives than what Komodo can provide. The reason we don't have the best possible engine to show alternative moves is Stockfish's Licence, it is wanted that Komodo's code remains closed because it's commercial, the main reason the MCTS system was implemented was to increase Komodo's sales, so it wouldn't have made sense to implement some Stockfish MCTS that would outperform Komodo at this, because at least like this, it could be claimed that Komodo is the best in the world at something, and that requires closed source.