Stockfish 15.1 with New Evaluation is Available on Chessify

This new release of Stockfish comes with several impressive upgardes. It introduces version 5 of the NNUE neural net architecture, a new evaluation method, and importantly, enlarged training data which includes Fischer random chess (FRC) positions.

Stockfish 15.1 can now be used on Chessify for free at 1000 kN/s speed. You can increase the speed to up to 1,000,000 kN/s by getting a Chessify plan.

Fischer Random Chess

The training data of Stockfish has been extended to include Fischer random chess positions. This resulted in a whopping up to 50 Elo rating gain for doubly randomized FRC (DFRC).

New evaluation

The Stockfish team also introduces a new convention for the evaluation, where +1 is no longer tied to the value of one pawn but to the likelihood of winning the game. 

While playing against an equally strong opponent, Stockfish has now a 50% chance of winning the game when the evaluation is +1.

The overall performance of the world's strongest chess engine has been further improved. Stockfish 15.1 wins two times more game pairs than it loses against Stockfish 15.

You can find full information about the new Stockfish version on the official website of the engine.

To use Stockfish on Chessify for free, register on If you want to see the options of up to 1,000,000 kN/s speed servers for Stockfish, visit our pricing page.

What people say about us


Train like a Grandmaster

Join 150+ GMs on Chessify Cloud to level up your training. Analyze securely with user-dedicated cloud servers at up to 1 BIllion NPS speed

Let’s get in touch!

We usually reply in a matter of a few hours. Please send us an email if you have any questions or visit our FAQ page for quick help