How hard is it to sweep a doubleheader?

This past weekend, I was lucky enough to attend a Red Sox-Yankees game at Fenway Park. Fenway is awesome, and I had a great time on Sunday. But, in a broader scope outside of my experience, the two teams were playing in a crazy four game set to open up the second half. After the Red Sox won on a walk-off-walk on Friday, the Yankees won a 16-inning thriller on Saturday. On top of all that, the two teams had a doubleheader on Sunday.

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I went to Game 1 of the doubleheader, which the Yankees won, 3-0. CC Sabathia wasn’t phenomenal, but he was good enough, and that was all that mattered. Once the game ended, I told my friends that the Red Sox were definitely winning Game 2. I had seen enough doubleheaders in the league, and in my mind, it is hard to sweep.

I turned out to be right. Relatively speaking, the Sox offense came alive in Game 2, mainly sparked by Mookie Betts’ home run over the Green Monster in the 3rd inning. Boston won 3-0, confirming my belief.

This doubleheader non-sweep piqued my interest enough to inspire this article as I wanted to know the answer to the simple question: is it hard to sweep a doubleheader?

Theoretically, a sweep of a doubleheader should happen 50 percent of the time. There’s only two options here: a sweep or not a sweep. I’m not worried about home team sweeps or away team sweeps, just sweeps alone. So, let’s dig into the data.

Using data from Retrosheet, I found that there have been 231 doubleheaders from 2008 to 2017. How many were sweeps? 120. That’s approximately 51.9 percent of all doubleheaders. This amazes me because the figure regresses so well to the theoretical probability. It’s like flipping a coin; the more you do, the more likely you will see your heads and tails figures move towards 50 percent.

Why is this amazing to me? Let’s think about the actuality of a doubleheader situation.

Playing two games in one day is tough. For Major League hitters, that means doing background research on two starting pitchers, all while having to play at the top of their games for eight to ten at bats as opposed to the four or five they’re likely to get in a normal day. It also means likely sweating out in the heat for one game, before coming back to play a second game a few hours later. Yes, these are professionals, and they should be able to handle two games, but at the same time, these two games are being played on the heels of a game the prior day, a game the day before that, etc. Playing in a doubleheader is much easier to do if you aren’t playing every day. It’s hard to always be at the top of your game, which is why we often see managers use doubleheaders as an opportunity to get bench players some playing time. That’s how I saw Deven Marrero, Sandy Leon, Tzu-Wei Lin, Austin Romine, Ji-Man Choi and Ronald Torreyes get starts in the first game. In game two, fewer reserves were used, but it still has an impact.

While it may be true that the lack of depth on both sides cancel out, the ability of a team to win the game is dependent on just a few players, making it harder to pull out a victory. At least in my mind, I think that in order to sweep a doubleheader, you need to have incredible depth, or at least significantly more depth than your opposing team to win.

This season, there have been 14 doubleheaders and just three have been sweeps:

• April 27 - St. Louis Cardinals sweep the Toronto Blue Jays at Busch Stadium
• June 10 - New York Mets sweep Atlanta Braves at SunTrust Park
• June 17 - Cleveland Indians sweep Minnesota Twins at Target Field

Let’s quickly break them down.

April 27: St. Louis Cardinals sweep Toronto Blue Jays

Game 1: Cardinals 8, Blue Jays 4 (11 innings)

The Blue Jays probably should have won this game, considering they had a 4-0 lead going into the bottom of the 7th inning. Mat Latos started and pitched surprisingly well through six innings, but some terrible relief pitching allowed the Cardinals to climb back into this game. A walk-off grand slam by Matt Carpenter sealed the deal. In a non-sweep world, this should have been the game that Toronto won.

Game 2: Cardinals 6, Blue Jays 4

The Cardinals handily took care of the Blue Jays in Game 2, scoring all their runs in the first four innings. No bullpen implosion in this one.

June 10: New York Mets sweep Atlanta Braves

Game 1: Mets 6, Braves 1

Game 2: Mets 8, Braves 1

There isn’t much to say about either of these games. Unlike the Cardinals-Blue Jays, where Toronto had an easy opportunity to win game one, the Mets handled the Braves with no issues in both games. It wasn’t the depth that won these games — Yoenis Cespedes and Jay Bruce homered in Games 1 and 2, respectively.

June 17: Cleveland Indians sweep Minnesota Twins

Game 1: Indians 9, Twins 3

Game 2: Indians 6, Twins 2

The Twins did carry a 1-0 lead in Game 2 of the doubleheader, but like the Mets example, this was a pretty clean sweep. Unlike with the Mets example, though, the Indians won with a combination of efforts from bench players and starters. Shortstop Erik Gonzalez had three hits, and Jose Ramirez hit two homers in Game 1; in Game 2, Austin Jackson had two hits including a homer, and Lonnie Chisenhall hit two homers.

What do these three anecdotal examples tell us? First, there is an argument to be made that depth is needed to sweep a doubleheader. Second, a doubleheader sweep could be because of some lucky bounces, where a win was gifted to them due to extenuating circumstances.

Overall, 2017 has lived up to my theory: doubleheaders are hard to sweep. There have been 14 doubleheaders thus far, and only three have been sweeps (21.4 percent).

But, as with anything, you have to look at the doubleheader in broader context. We cannot allow ourselves to be swayed by recency bias because it doesn’t match the broader trend.

In reality, how hard is it to sweep a doubleheader? It’s about as likely a coin landing on heads.

Devan Fink is a Featured Writer at Beyond The Box Score. You can follow him on Twitter @DevanFink.