Aroldis Chapman's Impact on the Chicago Cubs Is Bigger Than You Might Think

The Chicago Cubs just sold the farm in order to acquire Aroldis Chapman from the New York Yankees. Given how much they paid, can Chapman be worth the cost?

When you get that big paycheck every two weeks, your mind starts to drift off, fantasizing about that long-sought-after toy that had previously been out of reach. That object is suddenly a realistic target, and nobody would blame you for making the plunge and splurging a little bit.

The Chicago Cubs have been searching for this toy since 1908. Their stocked farm system was burning a hole in their pocket, and they finally found an area to overpay.

"Splurging" may be underselling the magnitude, but the Cubs must think that Aroldis Chapman -- arguably the best reliever in all of baseball -- is worth giving up one of the league's best prospects in Gleyber Torres along with three other players. They know what their target is, and they're going all out to get there.

The question now turns to how much better Chapman makes the Cubs. They already have a 97.4% shot at the playoffs, according to our algorithms, so discussion about his regular-season value is bordering on irrelevant. This is an acquisition geared toward winning when it counts.

Can Chapman make a difference in the postseason that's worth such a lofty price tag? Let's take a look.

Postseason Usage of Relievers

Because the sample size in the postseason is so small, the relative value of each and every inning gets blown up compared to the regular season. And as the past few Octobers can show you, there aren't many restrictions on the work a reliever can provide.

During last year's run to the World Series, the New York Mets trotted Jeurys Familia out 12 times for a total of 14 2/3 innings. They played 14 games and 134 total innings as two went to extras against the Kansas City Royals. This means that Familia threw 10.9% of the team's total innings in the postseason, the equivalent of throwing nearly 160 innings during the regular season.

The year before that, the Royals pitched Kelvin Herrera 15 innings and Wade Davis 14 1/3. This puts them at 10.5% and 10.0% of the team's 143 postseason innings in 2014. Again, these are significant percentages of the team's total innings controlled by high-leverage bullpen arms, exactly what the Cubs are expecting to get out of Chapman.

Let's assume that the Cubs use Chapman in a similar way to how the Mets used Familia or how the Royals used Herrera and Davis. Then, they're not acquiring a half season of a reliever; they're acquiring their opponents' pain and suffering for 10% of the postseason. It may not fully compensate for what they lose with Torres and company, but it shows that there is a disgusting amount of value in a reliever of Chapman's abilities in the playoffs. When you haven't won a World Series since before World War I, it's hard to fault the team for making such an aggressive move.

The Cubs' Bullpen Without Chapman

All of this discussion about Chapman could be moot if the team already possessed a shut 'em down, lock 'em out bullpen, but that's really not the case. Although they're above average, it's clear Chapman's going to make a difference.

As of Monday, the Cubs' pen was 12th in skill-interactive ERA (SIERA), putting them fifth among National League teams. That's certainly not terrible in a vacuum, but each of the four teams ahead of them is either currently in the postseason or within one game of it. There is a realistic scenario in which they would enter the playoffs with the second-worst bullpen on the National League side (the San Francisco Giants would likely take the crown, currently sitting in ninth place). This isn't a weakness as a whole, but it is when you compare it to their competition in the most critical games of the year.

Those bullpen numbers can contain a lot of noise during the regular season as you're not using Mr. Junkball Long Reliever in the playoffs. When you look at the individuals within the pen, you can see a potential three-headed monster forming at the back-end of games that could make the Cubs' unit absolutely lethal.

Prior to this trade, the Cubs had a dynamic duo to close things out in Hector Rondon and Pedro Strop. They entered today ranking second and fourth, respectively, in SIERA among qualified National League relievers. That's pretty sickly, and it's a much more optimistic view of the Cubs than the overall numbers painted. So why, then, would they need Chapman?

Let's go back to our discussion of postseason reliever usage. The Royals were able to get more than 10% usage out of both Herrera and Davis in 2014, meaning there were plenty of innings to go around. Even if the Cubs limit each of these guys to less exposure than that 10% mark, we're talking about over a quarter of the game in which the opponent's offense has very little hope. Wouldn't you take this type of silliness for multiple innings each and every game?

RelieverStrikeout RateWalk RateERASIERA
Aroldis Chapman36.7%6.7%2.012.14
Hector Rondon35.0%3.7%1.951.98
Pedro Strop33.3%8.2%2.872.40

Chapman is an upgrade over Strop, even if the gap isn't necessarily grotesque. But what's more important is that Strop is an improvement over whoever would have occupied that third slot without Chapman. Here, the Cubs have a wrecking ball waiting once you get to the seventh inning. Otherwise, although it's a respectable group, it's not necessarily something that completely alters your gameplan.


There are tons of reasons to object to this type of trade. You can say that the Cubs mortgaged too much of their future in order to improve now. You can also object because of the utterly abhorable domestic violence incident that led to Chapman's 30-game suspension to kick off the season. If we're viewing this from a baseball-only perspective, though, it really does seem as if Chapman will make a significant difference.

For a team like the Cubs with the playoffs being nearly a sure thing, Chapman's value is amplified. We've seen the past few years that relievers can play a major role in the postseason, and having a shut-down arm occupying over 10% of your innings is an advantage.

With Chapman, the Cubs now have a Royals-esque three-headed monster waiting at the final third of every game. Chapman, Rondon, and Strop will now be three of the best relievers in the entire National League, turning what was once a minor weakness into a bona fide strength.

At the end of the day, this move doesn't cripple the Cubs' farm system. Because of their intelligent moves over the past few years, they've still got a good number of young players down there who can contribute in the future. They had a surplus in an area the Yankees were looking to exploit, and while it may seem as if they overpaid, the impact of this move is undeniable.