Win expectancy, as measure by Fangraphs, is a probability that a team will win from the current situation in the game. If your team is down 3 – 0 in the bottom of the ninth, and your team is playing at home, it has a low probability of winning. If your team is the away team, well then you have 0% probability of winning. 0% is what happens when you’ve already lost. Any time the game is still being played, both teams have a non-zero-percent chance to win.
Looking at the win expectancy graphs for games can give us an idea of how those games unfolded. Not that we need to look at such graphs; if you watched the extra innings of yesterday’s game for instance, you probably don’t need a graph. But I find it fun to follow the win expectancy throughout a game. I am also a graph nerd.
Many games have relatively boring graphs, like those games played yesterday between the Astros and Orioles or Blue Jays and Giants. The M’s game last night was virtually a flat-liner for eight innings. No team managed an edge greater than 68.7% before the ninth inning. But the ninth through 16th innings took us on a roller coaster, and here’s the chart to quantify it:
Going into the bottom of the 14th, the Mariners’ win expectancy was at 0.4%. Four out of every thousand teams have come back to win after being down five runs in the final half inning. While the M’s went the way of the other 996, their path to get there was definitely a path not often traveled. Even when Seager stepped to the plate that inning with the bases juiced, the M’s win expectancy had risen to just 4.1%. I’m not sure if losing in this fashion is easier or harder than slowly getting further and further away from victory as the game goes on, but quantifying stuff is cool in my book.