Just how important is a home Knockout Round game? Well, in a word: very.
This week, the Audi 2018 MLS Cup playoffs get underway with four Knockout Round games, split between Wednesday and Thursday. FiveThirtyEight gives the mathematical edge to all four home teams, which corresponds with the history of the knockout round game.
Since 2011, when MLS first introduced a knockout game, the home team advanced 15 out of the 20 games (75 percent). Since 2015, when the league moved to the current 3rd vs. 6th/4th vs. 5th format, the home team has advanced 9 out of 12 games (75 percent).
On Wednesday, NYCFC host Philadelphia Union (7 pm ET | FS1, UniMás in US; TSN, TVAS in Canada) before FC Dallas welcome the Portland Timbers to Toyota Stadium (9:30 pm ET | UniMás in US; TSN, TVAS in Canada). The next night, D.C. United are home to Columbus Crew SC (8 pm ET | FS1, UniMás in US; TSN, TVAS in Canada) before LAFC vs Real Salt Lake (10:30 pm ET | ESPN2, UniMás in US; TSN, TVAS in Canada) closes out the opening round.
Then, it's onto the Conference Semifinals, starting Sunday.