The engine plays itself on a game clock while the score it reports for each move is plotted, from white's side, with the time the time manager chose to spend on each move as bars underneath. Behind it a pool of workers takes every position of the game and searches it to a fixed depth, plotting a second line, so the quick clock search and the deep search can be compared. Where the two lines part is where the game was decided, or where the quick search was wrong. Scores are clipped to ten pawns and a mate is drawn at the edge. The first four plies are random so each game is different. Both sides use the same worker, which is fine since they are the same engine. Game end is checked by the page: checkmate, stalemate, threefold repetition, fifty moves, insufficient material or a 300 ply cap.
score: quick clock search in blue, deep search in red. bars: time per move