Jostle is played on a 10×10 board with the following setup:
Each turn players one of their one orthogonal step to an empty square of higher value than the square they're leaving.
A square's value is defined as the number of orthogonally adjacent friends minus the number of orthogonally adjacent enemies.
If after jostling the opponent has no legal move, you win!
To the left Player 1 can move b2 east since b2 is worth -1 (1 adjacent friend, 2 adjacent enemies) and c2 will be worth 0 (1 friend, 1 enemy). She could also move c3 there. a2 cannot move at all.
To the right, after Player 1 moved b2 to c2, Player 2 can move b3 west or south (in both cases going from -2 to -1). She could also move d2 (-2) to d3 (-1) or d1 (0).