What it means
A double attack is any single move that creates two threats at once. Your opponent can only answer one of them, so the other one wins. A fork is a common kind of double attack.
You've shown this pattern in 2 of your last 5 games
In this game
Move #15 · Arrow: the key move · Glow: the key squares
Go to move #15 on the board →
Tap a move to preview it on the board above. Use "Go move" to jump there.