Via BBTF, did the Cubs cost themselves home field advantage in the NL Wild Card game?

To be fair, it’s a small bite. In baseball, home-field advantage means the host wins roughly 54 percent of the time. The thing here is how obvious the counterfactual is to work out. The most basic illustrator is WAR—Wins Above Replacement, which offers an estimate of how many wins an individual player creates. We’ll use Fangraphs’ version of the stat: Bryant didn’t get called up until April 17, and in the eight games (plus one rainout) before his arrival Cubs third basemen combined for an offensive WAR of just under negative 0.3. (Four hits in 29 at bats will do that to you.) Over the next 154 games, Bryant played in 151 and produced 6.5 WAR. If we assume he would have hit at the same level in the games he missed (not a given, since his best months came in August and September), Bryant could have added just over 0.3 extra WAR.

Swap the cruddiness of Mike Olt for the excellence of Kris Bryant and you get six tenths of a win. This kind of direct conversion isn’t really how WAR works, but the size of the swing (especially in a mere eight games) shows how much Bryant’s presence would have helped the Cubs’ in their retroactive search for that extra win.

Another reason to change the rules so it’s not service time, but seasons in the majors that control arbitration and free agency.