One benefit of the White Sox' lefty-heavy rotation

We spent Thursday marveling over the White Sox' historical inactivity on the basepaths, so you may be pleased to know that White Sox pitchers found a way to make opponents' running games even less effective.

Nature is on their side for once. There's been a lot of mild concern over the left-handedness of the White Sox rotation over the last few years, which was taken to a new level in 2015 as Carlos Rodon joined Chris Sale, Jose Quintana and John Danks to give the Sox four southpaws. That's highly unusual, and it often prompts questions about whether a right-hander is needed.

While the Sox rotation should eventually get another righty by sheer odds once Danks cycles out of the rotation, I don't see balancing the rotation being a priority. Danks was the only lefty who was really thumped by righties this year. Quintana had typical traditional splits for him, and Rodon's splits were magnified by his dominance over lefties. In a weird twist, Chris Sale kept righties off base better than lefties this year -- he just gave up all 23 of his home runs to righties this year (19 of them to Ryan Raburn).

Though Sox starters may have been slightly more vulnerable against right-handed lineups, the baserunners Sox starters did allow had a difficult time moving, even though none of their catchers were especially adept at throwing out basestealers.

On the whole, the White Sox rotation ended up with less activity than the rest of the league.

(The White Sox were the only team to get more than 1,000 innings from the rotation. The Astros were second with 983, and the Indians third with 979.)

But that's not that impressive in and of itself. It's only really noteworthy when realizing that most of that activity was concentrated in the first half. Look what happened after the All-Star break:

Only the Toronto Blue Jays' rotation (led by Mark Buehrle) was harder to steal on than in the second half than the White Sox rotation. Moreover, that strong finish allowed this Sox staff to be the second-hardest rotation to run on out of any White Sox rotation in the U.S. Cellular Field era, and continued a trend of limiting baserunning activity. The starters have allowed fewer than 80 attempts in each of the last three seasons, after averaging 104 from 2008 through 2012 -- even with Buehrle in tow through 2011. That's a point for severe left-handedness.

If you've read South Side Sox closely, you may know who is most responsible for that second-half improvement. If not, you'll know in a bit.

Baseball Prospectus has a stat called Takeoff Rate Above Average, which Harry Pavlidis drew my attention to in a different discussion on Twitter. The definition of TRAA:

The model for TRAA (Takeoff Rate Above Average) is similar to SRAA, but more complicated. With Takeoff Rate, we don't care whether the baserunner actually succeeds in stealing the base; what we care about is that he made an attempt.

And part of the complicated process mined from play-by-play data:

@MattEddyBA Right, and once you mix in lead runner, game state, catcher, who is at the plate ... you get those subtle adjustments we seek.

— Harry Pavlidis (@harrypav) October 7, 2015

The leaderboard has Jon Lester being 16 percent easier to run on than the rest of the league, which makes sense since he's terrified of throwing to first. As far as the White Sox are concerned, they all grade out well when it comes to their takeoff rate, as Carlos Rodon is the only one who allows an above average frequency of attempted basestealers.

• Carlos Rodon: 0.63 percent
• Jose Quintana: -3.28 percent
• Jeff Samardzija: -4.31 percent
• John Danks: -5.38 percent
• Chris Sale: -6.42 percent

There are only 14 pitchers in baseball who runners try less than Sale, and Buehrle leads the way at -13.74 percent.

That the Sox only have one starter that's run on at an above-average rate is encouraging enough, especially when you think back to the days of slow-to-the-plate righties like Gavin Floyd, Edwin Jackson, Jose Contreras and Freddy Garcia. Danks has also improved considerably in this regard, which is one of the ways he's adapted in order to not die.

I was surprised that Rodon was the starter that stifled the running game the least. The consolation prize is that nobody embodies that second-half improvement better. I've mentioned it before when reviewing his season, but somewhere along the line he flipped the switch and became impossible to steal off. Let's personalize the above charts for Rodon:

That's basically a transformation from Lester to Buehrle overnight. And because of that, we start to have an idea of what previous Buehrle-led staffs might've looked like without lumbering righties dragging the team's numbers down.

Speaking of Buehrle-led staffs, the one rotation that suppressed the running game better than the 2015 White Sox? The 2003 staff, which featured not just Buehrle, but a Bartolo Colon who never ceases to amaze:

Yet the kill rates for the catchers -- mainly Miguel Olivo and Sandy Alomar Jr. -- were dragged back to average by a bullpen that allowed 34 stolen bases in 37 attempts. They went 12-for-12 combined off Kelly Wunsch and Damaso Marte, both of whom were left-handed. Relievers generally don't hold baserunners as well as starters do, but even the 2015 White Sox were 27-for-34.