The A’s, Pitchers, and More Fun with Cascading

Every year, baseball’s intelligentsia settle on a new sleeper team. The ballclub in question is usually young, with a bunch of players coming off strong seasons. Because of those players’ youth, we assume continued progress the next season, even a playoff run.

The A’s have started to crystallize as 2011’s go-to sleeper team. They went from 75 wins to 81 in 2010. They’re armed with a universally-admired, young starting rotation, and have recently upgraded their offense and their bullpen.

Niche blogs have jumped on the bandwagon. Sabermetrically-inclined analysts writing for mainstream sites have done the same. Buster Olney’s on the A’s too (Insider subscription required), profiling Gio Gonzalez as one of the key young stars who could propel Oakland to the postseason this year.

Is everyone doing this wrong?

One statistical concept you’ll frequently see discussed ’round these parts is regression to the mean. In baseball terms, if a player enjoys an extraordinary season, one well outside historical norms, odds are he’ll follow with a season more in line with his typical production. This is a trickier concept to nail down in the case of younger players. Since their track record is so short, we don’t yet know what a typical season might resemble.

That’s where we are with much of the A’s roster, especially the starting rotation. Let’s take a look at some numbers for this fab four:

Player              Year      ERA    FIP   xFIP
Brett Anderson      2009     4.06   3.69   3.61
Trevor Cahill       2009     4.63   5.33   4.92
Gio Gonzalez        2009     5.75   4.47   4.02
Dallas Braden       2009     3.89   3.73   4.80

Player              Year      ERA    FIP    xFIP
Brett Anderson      2010     2.80    3.21   3.75
Trevor Cahill       2010     2.97    4.19   4.11
Gio Gonzalez        2010     3.23    3.78   4.18
Dallas Braden       2010     3.50    3.80   4.41

None of the A’s top four starters had ever spent a full season in a starting rotation before 2009. So we’ve got two years of reliable data to go on. What does this relatively limited dataset tell us?

Brett Anderson is very good. He’s made 49 major league starts, struck out more than 7 batters per 9 innings, walked just over 2, and yielded just 26 homers in 288 innings (0.81 HR/9 IP). We’ve now got two seasons suggesting he’ll allow about three and a half runs (or fewer) per nine innings after stripping out the effects of his defense, or a smidge more if we normalize his home run rate to account for Oakland’s cavernous dimensions. He’s the clear staff ace.

After that? Who knows.

Cahill came with a great pedigree as one of the best sinkerballer prospects in the game, someone who’d keep the ball in the park and induce a ton of groundouts. But he’s struck out just 5 batters per 9 IP so far in the big leagues, struggled with command in his rookie season, and benefited greatly from hitters pelting grounders right at fielders last year (.236 batting average on balls in play).

Gio Gonzalez is a left-hander with a live fastball (average velocity 91.5 mph) and one of the deadliest curveballs in the game when he’s on (an incredible +21.1 run value last season). He also walked more than 4 batters per 9 IP in 2010, and that’s after slicing one full walk per game off his record from 2009 levels and nearly halving his HR/FB rate.

Dallas Braden‘s skills appear the most stable. He’ll strike out five and a half, walk two and a half, induce more flyballs than groundballs, and use his home park and his outfielders to limit the damage. When he’s on, this happens. But for the most part, he’s a reliable number-four starter.

So we’ve got one excellent starting pitcher, one a tick better than average…and two guys who could be anything from fringe Cy Young candidates to slight liabilities depending on where their careers go from here (Gonzalez is 25, Cahill is 22).

Projecting these four pitchers to continue their progress is an iffy proposition. The idea that position players peak in their mid-to-late 20s is a commonly-accepted concept in baseball circles. But pitchers are more unpredictable, with injuries and sudden, dramatic changes in performance more common. You can’t project a neat bell curve for hitters topping out at age 27; you can’t even begin to try for pitchers.

There’s another variable making A’s prognostication even tougher. Last week, Matt Klaassen wrote about Cahill parlaying batted ball luck into a season in which his xFIP was more than a full run higher than his ERA. But Cahill was hardly alone in that discrepancy: Key relief pitchers like Andrew Bailey (1.47 ERA/3.80 xFIP), Brad Ziegler (3.26 ERA/4.36 xFIP) and others added to the gap. The A’s tied for 3rd in MLB (best in the AL) with a 3.56 ERA last season. But they ranked just 14th with a 4.24 xFIP. That was the biggest ERA-xFIP spread of any team in the American League, by a wide margin.

Though xFIP does seek to normalize home run effects, neither it nor its FIP cousin account for the entirety of ballpark effects. Simply regressing A’s pitchers home run rates to league average may not be enough to override Oakland Coliseum’s extreme homer-suppression (0.701 HR factor) last year, and the park held down singles (0.923) and doubles (0.903) as well. So even when you adjust for the A’s stellar gloves (no infield fared better last year than Daric Barton, Mark Ellis, Cliff Pennington and Kevin Kouzmanoff, and Coco Crisp remains a very good fly-chaser), we’ve still got a lot of uncertainty on our hands, and the potential for regression – how much of their success was the defense and park, and how much was good fortune? It’s hard to tell, though the fact that the A’s have a team ERA of 3.96 against a 4.34 xFIP since 2002 (a sample of over 13,000 innings) suggests that we probably shouldn’t expect Oakland pitchers to post equal numbers.

The A’s have moved to mitigate some of that uncertainty. They’ve upgraded their bullpen (Grant Balfour at 2 years/$8.1 million is a fine deal in this market, and Brian Fuentes is reportedly on his way) and revamped their lineup (welcome Hideki Matsui, Josh Willingham and David DeJesus).

But even those moves are far from a sure thing. Matsui is 36, with diminishing power. Willingham is a defensive liability who’ll give back some of the runs he adds offensively. DeJesus has only topped 144 games played once in his career. The A’s made an aggressive run at Adrian Beltre for the second straight off-season, but again came up short; he would have offered a much easier shot at a multi-win upgrade than any of the players who ultimately signed.

What we’re left with is…a whole lot of potential variance, same as last year. If the A’s are going to unseat the Rangers for the AL West crown, they’ll probably need further improvement – or at the very least continued strong performance – from their top four starters. Will it happen?

If there’s one reason for A’s fans to be optimistic, it’s the same reason I expressed concern about the Brewers’ chances last week: cascading. One of my favorite pet theories (I have many; don’t ask me about teams’ rigid bullpen usage unless we’re WAY off the record) is that no matter how much we try to adjust for the effect of defense on run prevention, we can’t fully capture its impact. When Mark Ellis ranges into the hole to snag a sharp grounder and end an inning, he’s preserving his pitcher’s pitch count, helping him avoid pitching deeper into an inning under duress, and allowing him to go deeper into games, with less injury risk. If Anderson, Cahill, Gonzalez and Braden stay healthy and go deep into games, that’s fewer innings for weak replacement starters, fewer innings for the bullpen’s weakest arms, and a clearer path to Andrew Bailey and the end of a ballgame.

Park factors may offer a similar cascading effect. If Dallas Braden knows he can get by without overpowering stuff, leave a ball up and know his ballpark will prevent an Earl Weaver Special, that can make it easier for him to get more outs earlier in the count, and reap the same health and bullpen benefits that a great defense provides. I would love to see more granular research on particular pitching staffs, their performance in relation to defense and home park, and if we’re missing something in our typical adjustments. At the risk of angering the small sample size gods, I think there’s plenty of interesting work left to be done.

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Jonah Keri is the author of The Extra 2%: How Wall Street Strategies Took a Major League Baseball Team from Worst to First -- now a National Bestseller! Follow Jonah on Twitter @JonahKeri, and check out his awesome podcast.

20 Responses to “The A’s, Pitchers, and More Fun with Cascading”

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  1. suicide squeeze says:

    Very reasoned take on the A’s….glad to have you on Fangraphs. As a A’s fan, I know I have to temper my expectations, but I can’t help but be excited for this season. If nothing else, there’s an insane amount of depth on this team that should come in handy when players inevitably get injured.

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  2. Danmay says:

    As another A’s fan; I think this is a well reasoned, interesting write-up.

    Regarding cascading: Sometimes I really get the impression that Billy Beane is literally expirimenting. I will be watching closely to see how this pitching staff, specifically Anderson, Gonzalez. Cahill, and Braden, does this year.

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  3. Scout Finch says:

    How about a Colosseum park effect accounting for those foul balls that don’t quite make it to the seats but rather find a glove for a foul out ?

    Got to like what the A’s are doing in spite of relocation/financial woes. They should definitely compete. Who’s to say the Cliff Lee-less Rangers will pitch as well as they did without him last year? Furthermore, the Halos didn’t exactly have an inspiring offseason. Who’s the better team on paper between A’s & Angels ? Dunno. Seems like a wash.

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    • John says:

      The exact same can be said of Oakland’s staff. I highly doubt they keep their ERAs where they are. Will definitely end up normalizing. What I find interesting is that case of what if both the Rangers and the A’s staffs regress? That would be even more interesting to see who comes up with the better solution.

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      • ChipJack says:

        I’m expecting to see more regression from the Rangers this year and a bit more progression from the A’s. They were still “in the hunt” late in the season last year. I also agree with the presumption that the Colossus-eum needs to be studied for the foul ball outs as well as those long-ball stymieing bleacher seats.

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      • FaStRmAn says:

        Who is to say the A’s young pitchers dont IMPROVE over last years numbers. I know the sampling size is small, but I see a trend toward improvement. A year more experience is always good for young players. As an A’s fan, I’d prefer to see the A’s young staff as a potential strength that is improving.

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  4. Chris says:

    You seem to be a little more down on Gonzalez than Cahill, but from a numbers stand point it seems that Gio has much more upside and should fair better. That is, of course, as long as he can limit the free passes. But still, even if he maintains a 4BB/9 rate, as long as he can capitalize on his defense and get the K’s, he’ll do well over the course of a season.

    Cahill’s FIP and xFIP to ERA gaps scare me going forward.

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  5. Talent Scout says:


    Glad to see you’ve brought your enlightened analysis to FG, the arrogant college kids posing as writers here had driven off many of those you’ve been reaching thru alternative methods.

    On cascading, yes: most definitely works and was used most recently by the Padres who may even have remnants of one of there “secret sauce” KPI’s still exposed on BP.

    Beyond just merely non-linear stat measures, though, the central idea your on to is a valid one: attrition warfare in baseball!

    Not a new concept at all for baseball managers, but the Sabr crowd hasn’t ever captured the behavior as I suspect interaction effects are either ignored or not appreciated as it runs counter to a bias for fantasy league style scoring.

    Keep up the great work and look forward to your upcoming book & future articles.

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  6. Robert Thacher says:

    The additions of Balfour and Fuentes should allow for an easier work load on the young pitchers,and lessen the pressure on the young relievers. Should balance out the regression factor. And, for every player that regresses, there is one who will improve.

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  7. PL says:

    You don’t think the defense can keep up the massive differential between xFIP and ERA? Its not like any of these defenders are getting old. Those who dont want to hold their horses will say the A’s rotation is overrated, but going off 2 years of sample data doesn’t seem wise. I think these young A’s players are a year or two away from knowing what they exactly bring to the table.

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  8. Nik says:

    I think that the cascading effect theory is spot on. That cascading effect was explained in a presentation by someone from SABR as the secondary effect of good defense on pitching. Basically at the extremes of defense, the allocation of high leverage innings can go to the best pitchers or the worst pitchers because of the amount of pitches saved/lost by good/bad defense.

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  9. Jonah Keri says:

    It was Vince Gennaro, and yes, great presentation. I referenced it in the Brewers pice:

    (Also thanks for the support gang, really is much appreciated)

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  10. Ty says:

    Great article. The first one I’ve read in a long time, since I did not like the style/attitude of many of the writers.

    Very refreshing. Thank you.

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  11. Brandon says:

    If I recall correctly, the Coliseum also has an abnormal amount of foul territory. Just a guess, but this would PROBABLY aid flyball pitchers more than groundball pitchers – a grounder foul is just a strike (and probably unaffected by park effects) while foul flyballs can turn into outs.

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    • Jon says:

      The most popular reason the A’s home yard helps pitching is the foul ground. Next is usually something like “roomy Col.,” or “big dimensions.” No.

      It’s quite possible the thick, heavy, damp, cool night ballgames air is the biggest culprit to hitters. This is so rarely noted except by A’s fans from the bay area it continues to shock me (and why whenever i see a post like this, i try to remind folks that despite being in CA, and baseball season being in the warm months of the northern hemisphere, the bay area at night for almost all of baseball season is quite underrated in how cold/damp it feels.)

      This simply hurts both the comfort zone of the hitter himself and how far his batted ball travels at the Col (and SF. LA and SD to a lesser degree, but there too. I think the Angels are far enough inland.) Pacific Ocean creates much different coastal weather than Atlantic and this often alludes folks who shouldn’t have any reason to know.

      So yeah, cold thick night air almost every night game and foul ground.

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      • Chris says:

        Does AT&T really notice that much of a difference in climate? Can’t you see the Colosseum from AT&T when it’s not socked in? They’re right across the bay from each other. Otherwise, this is a very true statement and the spacious OF only magnifies the affect.

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      • Mike says:

        Yeah, on days/nights with no fog, you can easily see the Col. from ATT. I’m also pretty sure, ATT is colder/damper than the Col. on most nights, I’m not sure he really wanted to mention SF with LA and SD.

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  12. Jon says:

    Chris and Mike.

    Firstly Mike. I didn’t mention SF with LA and SD. There’s a period between them.

    Secondly, Chris, when you say “spacious outfield” you’re making the very mistake i’m talking about.

    The Oakland Col does NOT have a spacious outfield. It has a VERY NORMAL set of dimensions. People, for some reason, continue to think it’s a big yard (maybe due to the large foul ground, which only effects foul pops.)

    This is what i’m trying to get at.


    Oakland Col has lot’s of foul ground, VERY NORMAL dimensions (NOT ROOMY, not spacious etc, once and for all,) and the cold, thick night air is THE biggest reason pitchers have an advantage over hitters.

    Most folks just cannot grasp this as Oak is in CA and CA MUST be warm most of the time, or at least not as cold as some guy says. Even looking at temps, one still doesn’t grasp how it’s a damp, ocean air cold, and it really feels COLD.

    This is also one of the reasons the A’s don’t draw as well as they could. I’m not saying they’d draw great otherwise, and they have drawn well despite the weather, but if the inner bay area had more than one, maybe two warm nights PER YEAR, the A’s might draw, no would, draw better. I know personally the weather does keep me from going sometimes. Hard to explain to folks from outside the area, but it is simply FREEZING at night most spring/summer nights in the inner bay area.

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