When the Astros acquired Ken Giles back in December, it felt like a logical next step for a team on the rise. Houston’s built a powerhouse around good drafting and developing—young stars Carlos Correa, George Springer, and Dallas Keuchel might even be better than advertised—and getting Giles from Philadelphia represented a win-now approach for an organization shedding the habits of its slow-burn rebuild.

The expectation was that Giles would take over the closer role from the soon-to-be 32-year-old Luke Gregerson, demoting the former ‘Stros closer back to a familiar setup role while making the bullpen that much stronger. That expectation was curiously not met when the Astros announced earlier this month that Gregerson would remain the closer, with Giles being used in “a more versatile role that can help [the Astros] win the most games.” What are the Astros thinking?

Maybe the Astros think Gregerson is better than Giles
It seems important to address the elephant in room here: Giles hasn’t performed well since joining the Astros. Now that performance consists of a whopping 9 1/3 spring training innings and 2 2/3 major-league innings (stats through Monday’s games), but over those 12 frames he’s already given up three home runs, one fewer than he surrendered in all of 2014 and 2015 combined.

That’s perhaps more of a red flag about Giles’ past good fortune with the long ball than it is a predictor of anything to follow in 2016. In his first two years in the majors, Giles produced a 47 percent groundball rate while allowing just three home runs, thanks in large part to a HR/FB percentage that sat at an unsustainably low 3.1 percent. Among relievers with at least 80 innings pitched over that time span, only Wade Davis and Blaine Hardy have posted lower HR/FB rates.

The other concern is Giles’ slight downtick in velocity. According to Brooks Baseball:


Fastball Velocity

Slider Velocity

2013 (AFL)












If you examine Giles’ month-by-month numbers, you’ll note that he started out 2015 at just 95.77 mph before gaining speed during the summer months. Notably, however, his velocity dipped in August, September, and October last season. That’s something it didn’t do in 2014, when he recorded his highest monthly velocity (98.43) in September.

On the other hand, there’s the veteran Gregerson who’s coped with declining velocity of his own by switching to an almost exclusively sinker-slider repertoire and walking fewer batters, highlighted by last season’s career-low 4.2 percent walk rate. Gregerson’s career cFIP sits at 83—it’s been in the 80s for four straight seasons—just nine points higher than Giles’ 2015 mark. PECOTA not surprisingly prefers Giles, but the difference between these two might be closer than you think, especially if the Astros identified something askew with Giles in spring training.

Maybe the Astros think they can save money with Giles as non-closer
Past research indicates that teams can save big money by waiting to give the closer’s gig to young relievers until after they reach arbitration, a factor Ben and Sam discussed on Effectively Wild last week. Giles doesn’t reach arbitration until 2018, which happens to be the same year Gregerson’s three-year, $18.5 million contract expires. While save counts can only have minimal impact on Gregerson’s current contract, Giles could end up earning a lot more dough if he’s able to add more saves to his ledger before 2018.

The Astros are currently in solid position payroll-wise without an albatross contract on the books, but one of the burdens of having a lot of good, young players is that eventually those guys will get paid. Keuchel currently makes $7.25 million after his first year of arbitration; Springer hits arbitration for the first time next offseason; and a Correa extension seems imminent—and likely pricey. If the Astros can save 5 or 10 million future dollars by reducing Giles’ save total, there’s a decent chance they’ll do it.

Maybe the Astros think they can improve their club with Giles in a versatile relief role
Let’s concede that the Astros prefer Giles to Gregerson—they aren’t the type of team to get swayed by small sample sizes, and Giles has performance and age on his side. Plus, they sent an impressive haul of talent to the Phillies for Giles, a package that included former first overall draft pick Mark Appel and Vince Velasquez. Let’s also concede that Houston’s main concern isn’t the money eventually owed to Giles through arbitration. Maybe they just think this is a good baseball move.

The long-held sabermetric belief on relief aces is that they’re wasted in rigidly defined closer roles, and that they should be deployed whenever they’re most needed—like in a tie game in the eighth inning against the heart of the opposition’s order or to get out of a bases-loaded, no out jam in the seventh.

Using Play Index, I looked at every high-leverage situation—2.0-or-higher Leverage Index—that occurred in innings five through nine in Astros games last season. (I omitted innings one through four because it’s unlikely an ace reliever would be called upon that early and also innings 10-plus because things can get weird in extras.) Here are the results:


High-Leverage Situations

High-Leverage Percentage

Average Leverage Index





















You can see that for Houston last season the ninth was indeed the most important inning—over 20 percent of all plate appearances in the ninth came in high-leverage situations and the average LI of 1.11 was greater than any other inning. On the other hand, look at how close the seventh inning came in all three numbers listed above. There were actually more high-leverage situations in the seventh than in the ninth last year, though the high-leverage percentage in the ninth was slightly higher because teams don’t always pitch in the game’s final inning. Once you add up all the high-leverage situations in innings five through eight combined, it’s a runaway.

I also looked at each game to see what inning held that respective contest’s highest leverage moment (again, focusing on innings five through nine):


Percentage with Highest LI of Game











Look at that fifth inning! Maybe Giles should work exclusively in the fifth . . . or maybe not. The fifth rates well here mostly because of blowouts, not necessarily because it contains a bunch of hidden crucial moments.

What we’re more interested in are the later innings, and again we see that there’s not a big difference between the seventh, eighth, and ninth innings. Among innings five through nine, the highest leverage moment occurred in the seventh in 19 percent of Astros games last season compared to 18 percent for the ninth—though, again, there are fewer opportunities to pitch in the ninth. Of course, that’s kind of the point: Why save your best reliever for an opportunity that may never arise?

Now the Astros will have Giles available to pitch in all those game-changing situations that conventional closers are forced to let pass by, and they’ll still have a good reliever available if needed in the ninth. They’ll also likely save a bit of money down the road, keep a veteran reliever in Gregerson content, and avoid the possible pitfalls of a true closer-by-committee setup. If this looks like a good decision, it probably is one. We’re talking about the Astros after all.

What were you expecting?

Thanks to Sam Miller for research assistance.

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While watching him pitch vs. the Yankees, the Yankees announcers made a point about Giles' pitches being too straight and flat. One of the Yankee announcers (David Cone I believe) said that he needed to pitch up in the zone to be effective because pitching lower in the zone made his straight pitches too easy to hit.
It seems like this article started with the premise that the Astros are smart to use Giles earlier in the game when leverage matters most. Then it proceeded to show evidence that leverage is actually higher in the 9th inning. And then it concludes that the Astros are smart after all to use Giles earlier in the game.

Why can't sabre oriented writers just say that thing we've been screaming about for years with respect to using closers earlier just isn't that big of a deal?
Because "average" leverage is misleading. A smart team won't use Giles in average situations, it will pick the highest leverage to use him in. So when there is a high leverage situation in the 7th, they'll use him, but not when there is a low leverage situation. If you do this right, even though the average leverage in the 9th inning may be higher, by properly picking the right spots in the other innings you'll get a higher leverage (and perhaps a significantly higher one).
Yes, that is the theory.

What is your predicted magnitude of difference between Giles being used "smartly" in the 7th and Gregerson being used traditionally as a 9th inning closer?

Let's say Gregerson ends the year with a LI of 1.50. What will Giles be relative to that? 1.75? 2.0? 2.25?

The practical implementation of the theory will likely lead to an LI a lot closer to Gregerson's 1.50 (and maybe even lower!) than the people seem to think. But I guess we'll see.
Yeah, what jonathan said. What I was trying to show is that there are actually many more high-leverage situations in the sixth, seventh, and eighth than in the ninth alone--I know, not exactly groundbreaking. But the idea is that if the Astros use Giles optimally in those innings, they'll have both Giles and Gregerson pitching similarly important innings, with Gregerson still content as "closer" and Giles making less money in the future.

(Not saying I totally agree with messing with Giles' future arbitration if that's what's going on, but from the Astros' perspective it makes sense.)
Had Giles come to spring training and dominated - or even just pitched well - he'd be the closer; it's that simple. I'm thinking that he he felt a little pressure coming to Houston after the big package of players assembled to get him, plus the adjustment of playing for a team with expectations rather than the "extended tryout" vibe found on rebuilding teams. While Gregerson remains competent in a closing role for the moment, Giles should eventually ascend to the role - although there is still a lot of debate among stat heads regarding the value of hard throwers, most teams would prefer a strikeout pitcher at the end of games, especially during a pennant push or the playoffs.