The Reason Behind the Cubs’ Dominant Pitching May Surprise You (or Not)

The Chicago Cubs are on a roll lately, winning nine of their last ten games. Undoubtedly, there are a lot of reasons for their recent hot streak. Those same things have contributed to the Cubs holding the best record in baseball as we stand here 109 games into the season.

Kyle Hendricks takes the mound today for the Cubs and, of all the Cubs’ starting pitchers, he’s been the most pleasant surprise. He currently is second in all of baseball with a 2.22 ERA. There’s even been a whisper of the possibility of him getting some attention when it comes time to hand out the Cy Young Award later this year. He’s been that good.

The fact is that the Cubs have the best ERA in all of baseball. Their team ERA stands at 3.17 and that includes their starting pitching ERA which is sitting at 2.98 with the next closest team ERA at 3.35, not all that close. When I dug in to the numbers deeper, what I found was quite interesting.

The Cubs FIP (Fielding Independent Pitching – a measure that looks at what a pitcher’s ERA would look like given league average results on balls in play and league average timing, via Fan Graphs) is 3.68, which is good enough for fourth in all of baseball.

Now, of course, fourth isn’t bad, but I thought it was interesting that they dominate so much when you compare ERA – a stat that doesn’t have a way to adjust for a team’s defensive play – versus FIP – a stat that does account for and actually attempts to remove the impact of the defensive performance of the team.

Clearly the Cubs defense has benefited their starting pitching, but I wanted to know by how much. When you look at the difference between ERA and FIP (E-F), and compare it to the rest of the teams in baseball, you see that the Cubs rank first with an E-F of -0.60. The next closest team, the Texas Rangers, has an E-F of -0.41.

Cubs starting pitching E-F is first at -0.70. Not surprisingly, the Cubs have three starting pitchers in the top ten in E-F – Jason Hammel (1st at -1.21 E-F), Kyle Hendricks (3rd at -1.10 E-F) and Jon Lester (9th at -0.90 E-F).

A look at one defensive statistic, Ultimate Zone Rating (UZR), helps us understand why the Cubs lead the league in E-F. UZR gives a run value to defense, attempting to quantify how many runs were saved or given up due to fielding (Fan Graphs). The Cubs lead the league with a 42.7 UZR. The next closest team, the Toronto Bluejays, have a 33.9 UZR.

The Cubs also lead the league in one other important defensive measure, Batting Average on Balls in Play (BABIP), which, in this case, looks at the frequency with which the Cubs have given up a hit on a non-home run ball that is put in play. Their BABIP of .256 is the lowest in the league and one more illustration of how good the Cubs defense really is.

So while the Cubs’ starting pitchers are clearly on a tear, leading the charge for the team with the best record in baseball, the team’s outstanding defense has played a major roll in getting the Cubs, and their pitchers where they are today.