First of all, if you missed DFA's excellent Monday piece on Trevor Cahill, give it a look when you have a chance. With Jack Cust having taken his unique brand of walks and strickouts to Pike's Place Market, and with Adrian Beltre's destination and earnings no longer in limbo, Cahill stands alone as AN's most polarizing figure. That is, pretty much the only thing we can all agree on is that we can't agree on exactly how good the baby-faced righty is and/or will be. This is because when looking at Cahill's 2010 season on a 0-100 scale, depending on what you look at you are likely to draw highly disparate conclusions.
On one hand, at the most cursory glance (18 wins for a team with a mediocre offense, a 2.97 ERA pitching in the American League, a BAA (batting average against) of just .220), you might give Cahill a rating of "90" -- about the rating you would give a pitcher who wasn't quite a serious contender for the Cy Young award but who was "in the conversation for top 10"; not the elite of the elite but an excellent pitcher who is better than about 90% of his peers.
On the other hand, looking at the most sophisticated and predictive metrics (a tERA of 4.38, an xFIP of 4.11, an unsustainable BABIP of .236, and a K/9IP rate of just 5.40), you might give Cahill a rating of "60" -- about the rating you would give a pitcher who was slightly above average but needed a ton of luck, defense, and park advantages to produce great win, ERA, and BAA numbers; a decent pitcher who is better than only about 60% of his peers.
No wonder discussions about Cahill's skills are so contentious: On a 0-100 scale, a difference of 30 is huge! In order to determine Cahill's "true talent level" in that possible 60-90 range, we need to distinguish between the qualities Cahill can control and the qualities which depend on factors Cahill cannot control. This post attempts, after the jump, to answer the question of what rating Cahill really deserves going forward, and why -- specifically focusing on four key attributes Cahill actually brings to the table that make him legitimately better than the predictive metrics show.
Though the sample is still small because his career spans only two seasons, fielding metrics rate Trevor Cahill as one of the league's better fielding pitchers. This is highly significant because Cahill is strongly a ground ball pitcher, and thus how he fields his position is actually more tied in to his success than, say, how Barry Zito (a fly ball pitcher) fields his position.
Cahill's fielding stats may be enhanced by inducing more soft ground balls, which are more likely than sharp ground balls, line drives, or fly balls, to be fielded by a pitcher. But bear in mind that Cahill's nickname, "Pterodactyl," comes from his large "wingspan," so some of the enhancement may also come from his ability to reach more balls that are headed up the middle than other pitchers can reach.
Stop for a moment and just consider how significant it could be if a ground ball pitcher, who is his team's 5th infielder, can offer appreciably more range than average on fielding ground balls to the left and right sides of the diamond's spine. I don't know if the A's intentionally position Mark Ellis and Cliff Pennington a step more to the hole when Cahill is pitching (this is a question I intend specifically to ask Mike Gallego et al when I'm at spring training mid-March), but if so then by being able to rely on Cahill to stop more bouncers up the middle, the A's are simultaneously able to put their middle infielders in position to get to more ground balls between 3B/SS and between 1B/2B. That's three key holes on the infield better covered because of an attribute Cahill himself brings to the mound.
"Quality of Contact"
This is a controversial concept and one we do not yet have the Pitch F/X data to confirm or deny in a scientific and data-based way. I am honestly surprised, though, that it is so hard to get consensus on what seems to me like an intuitively self-evident notion: That not all pitchers induce batters to hit ground balls the same way.
It's not a matter of pitchers shaking off the slider, then shaking off the changeup, nodding their head to the third sign and intentionally throwing a "hit the top part but don't miss it entirely ball," which is a nonsensical notion. Here's what's going on...
There are some pitches designed to miss bats entirely. One, thanks to it's velocity, is the fastball. Another, thanks to the sharp break that makes it difficult to track, is the curveball. Another, due to its "late diving action," is the splitter. (Please note that when I refer to "late movement" on pitches, I am referring to what the batter perceives, not necessarily to the ball's actual path. What the batter sees/perceives/experiences is far more important than what is actually happening.)
Meanwhile, there are other pitches that are designed less to miss bats and more to miss the sweet part of the bat. One, thanks to its late movement, is the cutter. (There's a reason that Mariano Rivera breaks so many bats every season. Rivera has also put up solid K/rates in his career, but that is due, separately, to the unusual velocity and command he has with his cutter.) Another is the sinker, a pitch whose movement is significant enough to be hard to "square up," but which doesn't miss as many bats entirely because it lacks the velocity of a two-seam fastball or the sharp break of the curve.
Cahill's sinker has a ton of movement, much of it down and some of it in/away, and when batters make contact they often either "beat the ball into the ground" because they hit the top of the ball, and/or they hit the ball off "the sweet spot" of the bat (off the end of the bat or on the hands).
What this produces is a lot of medium ground balls (these are the routine two-hoppers to 2B, the tappers to 3B, the rollers to SS, etc.), and a lot of soft, or "mis-hit," ground balls (these are the dribblers in front of the plate, the choppers up the 1B line, the squibbers between the mound and 3B, etc.).
One rebuttal that has been made to the notion that Cahill is an outlier in getting an inordinate number of low quality of contact ground balls is that "the hardest ground balls to convert into outs are really hard grounders and really soft grounders. So is Cahill somehow magically avoiding difficult to field hard grounders while not avoiding difficult to field soft grounders?" The answer is no. He gets plenty of very soft grounders; he just converts more of them into outs than most pitchers do. Why? Because guess who his 5th infielder, the guy whose fielding ability comes into play a lot dribblers and squibbers, is? Trevor Cahill, one of the league's better fielding pitchers.
The Benefits of a Low "Slugging Against" Profile
Ground ball pitchers tend, by nature, to give up more singles but fewer extra-base hits, than average, simply because ground balls tend to find more holes than fly balls do but when not successfully fielded, fly balls have more of a tendency to become doubles, triples, and homeruns.
We've just looked at how/why Cahill might mitigate some of the inherent tendency to give up more singles on ground balls, by inducing a lot of choppers, bouncers, and squibbers, and then unleashing his pterodactyl wingspan on some of the balls trying to get through the middle.
However, just by simple regression -- be it of luck, defense behind him, or good old fashioned "nowhere to go but up" -- he is almost bound to give up more singles this year than he did in 2010, and if I'm a betting man he's also going to give up more HRs. But as a pitcher with a very good GB/FB ratio, one thing you can reasonably expect from Cahill is that he will limit the number of extra-base hits in general because limiting extra-base hits is one of the things extreme ground ball pitchers do well by the nature of their craft.
What happens when a pitcher gives up some walks and some singles, but not many extra-base hits? You get a lot of innings that go (out, single, out, walk, out), or (single, out, single, DP), or (out, out, single, single, walk, out), or (single, walk, out, DP), or (out, single, out, single, walk, out)...
What you're seeing is not a lot of runs, but a lot of guys left on base (or wiped out by DPs). Does this remind you of anything? Yes, that's right: Trevor Cahill turns opposing teams into the 2007-2010 Oakland A's offense! Run for the hills! Hide the children! Or don't, because that nightmare we have endured for years is in fact being perpetrated on the opposition.
Do the stats we have available confirm this? A league average "strand rate" is about 72%. Cahill's "strand rate" in 2010 was 76.5% (and remember that runners erased on DPs are not even counted as stranded). Unsustainable and bound to regress? Quite possibly. But will it regress all the way to league average? I'm not so sure it will. Cahill has a skill-set that makes it easier for teams to get runners on base than for them to efficiently move them all the way around. We've seen it for years, only to our great frustration, with Oakland's "middling OBP, middling BA, low slugging" offense.
This is a nebulous concept, but one I want to throw into the conversation because I think it is such an important one when looking at why some players improve, while some stagnate and others disintegrate before our very eyes. Baseball is a game of constant adjustments, and while talent, muscle memory, and health are among the factors that play clearly a huge role, don't be too quick to overlook how essential it is for players to be willing and able to adapt in order to survive and/or thrive.
On the more mental level, Bobby Crosby illustrates the pitfalls of a stubbornness that led him once to claim that "his batting approach worked for him in high school and would work for him now," and we saw what his refusal to embrace change brought him. On the more physical level, Crosby also illustrates the results of an inability to recognize a slider better than he did yesterday, so that pitchers have been able to fool him the same way for years.
In contrast, Cahill's teammates have marveled over his adaptability, even noting that he is unusual in his ability to fiddle with new pitches, or grips, or mechanics, in the bullpen, sometimes even fixing a problem during a start. (From the linked article by Susan Slusser: Messing around with grips and trying different things is the norm for him. He said that at one point last year, he threw a cutter for three games after trying one out while throwing on the side with Brett Anderson. "It seemed like he had a new pitch every day," Anderson said. "Like, 'Oh, I'm going to do this now, and I'll be in contention for the Cy Young.' Pretty crazy.")
Have we seen any concrete evidence of this? After failing throughout most of 2009 with a knuckle-curve that was not serving him well at all, Cahill developed a slider. It wasn't a good one, but it was a slight upgrade and Cahill finished the 2009 season a little stronger than he started it. Then he upgraded again, this time to a curve ball which was much more effective than the slider that had been a little more effective (or less ineffective) than the knuckle-curve.
That a 21-22 year old was able to adapt his repertoire, in real time, while pitching in the big leagues, is significant. The fact that Cahill appears to be ready, willing, and able to adapt is a very good sign if you're trying to figure out whether he will find a way specifically to improve his K-rates, or will find a way generally to adjust back to the adjustments batters make.
The Grand Conclusion?
What I have not discussed in depth are the factors that are beyond Cahill's control, and those are also very real. The home park he pitches in is very favorable to pitchers, the defense behind him is excellent and could not have hoped for better UZR showings in 2010, and no matter how much skill he brought to the party, Cahill's BAA (.220) and BABIP (.236) suggest that if Lady Luck played a part in Cahill's 2010 season, she was a huge fan.
At the same time, however, Cahill's own fielding ability, which is especially significant because he is a ground ball pitcher, his ability to produce weaker-than-average contract with a pitch that has exceptional movement to oft escape the sweet part of the bat or ball, his capacity to force teams to build station-to-station rallies, and his adaptability, are attributes that are within Cahill's control. He brings them to the mound in whatever park he pitches, in front of any defense, and within the framework of any level of luck.
For the sake of simplicity (since I have no exact way to assign them values), and round numbers, let's suppose that the four factors I have discussed at length (fielding, quality of contact, suppressing slugging, adaptability) average out to be worth, on that 0-100 scale, about 15 points total, and that the three factors outside of Cahill's control that are known to be key as well (park, defense, luck) average out to be worth, on average, about 15 total points as well.
You wind up with a pitcher who is, in fact, currently pitching at the level of about a 75, which is where I personally believe Trevor Cahill should currently be rated. If so, this would mean that if in 2011, you are hoping to see an 18-game winner with an ERA under 3.00 who is in the conversation for "Top 10 Cy Young award candidates," you are going to be disappointed. It would also mean you have a pitcher who, as he makes his Cactus League debut on or about his 23rd birthday, is better than 3/4 of his major league peers -- and that's a good thing to have.
Post Script: What might all this translate to in numbers, if Cahill completes a full and basically healthy 2011 season as a pitcher in about the 75th percentile? If you're letting park and defense enter the picture, perhaps it looks something like 15-10, 3.42 ERA with 190 IP, 165 hits, 75 BB, 120 K, a .240 BAA and a .280 BABIP, and if you're looking at more park and defense neutral stats perhaps it looks something like a 3.85 xFIP and a 3.68 tERA -- maybe a tad higher if Cahill, however "really good" or "only decent," does prove to be a bit of a true "FIP-buster" by nature.