Archive for Nate Robertson

Zack Greinke In ‘The Peripheral Disconnect’

Pitchers whose ERAs and estimators disagree are extremely interesting to analyze. On one hand, their signature run prevention mark might appear toward the top of leaderboards while the underlying numbers aren’t as fruitful. On the other side of the spectrum are pitchers like Zack Greinke, who, as Chris Cwik pointed out yesterday, has a vast disconnect between his ERA and FIP. In fact, it’s been that way since the first week of May when he came off of the disabled list.

His 2.63 FIP and 2.12 xFIP suggest that the newly-minted Brewers starter has been one of the best in the league. But Greinke’s actual 5.63 ERA is closer to the bottom than the top, and is three runs higher than his adjusted marks. One of the more popular stats here is E-F, a sortable number that measures the gap between ERA and FIP. Pitchers with a large separation are expected to regress in some fashion, because it is incredibly rare for anyone to finish with a huge disagreement between those two data points.

I thought about taking that concept a bit further and calculating the difference between ERA and xFIP, since the latter metric is a better predictor of future earned run average than its predecessor. This makeshift ‘E-X’ number would be measurable from 2002-now, and it piqued my curiosity to see which pitchers had the largest such gaps in that span.

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Where Did Those Tigers Go?

Back in 2003, the Detroit Tigers went 43-119, narrowly avoiding a tie with the expansion 1962 New York Mets for the most losses since 1900. Dmitri Young proved to be their top hitter with just +2.1 wins added, and Nate Cornejo led the pitching staff at +1.9 wins. At most, their top two players were league average. Hope sprung eternal in the motor city, however, thanks to the promising young arms of Mike Maroth, Nate Robertson, Nate Cornejo, And Jeremy Bonderman. Suffice it to say, none of the four have lived up to the hype sent their way several years ago. They might have a better track record than the Bill Pulsipher/Jason Isringhausen/Paul Wilson triumvirate of the Mets in the mid-90s, but the fearsome foursome has not met expectations.

Maroth became famous for losing 21 games, becoming the first pitcher to surpass the 20-loss plateau in over two decades. Many felt his varied repertoire, precision control, and ability to induce grounders would lead to a long and prosperous career. They were wrong, primarily because his putrid strikeout rates never factored into the equations. Throughout his career, Maroth’s K/9 has topped out at 4.95, though his career rate is lower at 4.34. He performed quite well in 2004-05, producing a sum of +5.2 wins, but injuries and the inability to miss bats finally caught up with Maroth in 2006, and he is yet to regain form. After splitting time with the Tigers and Cardinals in 2007, Maroth spent last season in the Royals farm system. He figures to repeat the act with the Blue Jays this season, though surgery may in fact end any chance of making the roster. This could very well be his last hoorah.

Teammate Bonderman graduated with a Masters in Underperforming from the JVIOSPBPR – the Javier Vazquez Institute of Solid Peripherals But Poor Results. From 2003-07, Bonderman never made less than 28 starts or pitched fewer than 162 innings. With a K/9 comfortably above 7.0 Bonderman also decided to limit free passes, reducing his walk rate from 3.5 to 2.5 per nine. Because of this, his win values have overstated actual contribution, similarly to Vazquez himself. Not that Bonderman has struggled, but his average of +3.4 wins/yr might not be a completely accurate depiction of his performance. Last season, things ironically went in reverse, as his 4.29 ERA bested a 5.18 FIP. He missed most of the 2008 season with injuries, however, and his return date is still up in the air.

Cornejo, the aforementioned top pitcher of that 2003 squad, managed just five appearances the following season, largely ineffective, before injuries got the best of him and forced an early retirement. His first name doppleganger, Nate Robertson, seems to be a mix of Maroth and Bonderman, posting average strikeout and walk rates, keeping balls on the ground, throwing strikes, and matching up ERAs and FIPs more closely. After struggling in 2003, Robertson averaged approximately +2.3 wins/yr from 2004-07, showing signs of improvement in a few areas but consistently serving as that slightly above average pitcher capable of toeing the rubber and logging innings with regular consistency. His performance dropped to just +1.2 wins last season in 28 starts thanks to a .343 BABIP, a reduced strikeout rate, increased walk rate, and higher home run rate. In actuality, the HR/9 of 1.39 is much closer to seasons past; the 1.11 in 2006 is the outlier.

Robertson recently stated that his time with the Tigers may be nearing its end given his demotion to the bullpen, meaning that Bonderman could be the lone remaining member of this particular prospect quartet. Hopefully he can brush aside the injuries that hindered last season’s production and get his career back on track, but this definitely goes to show how nothing is ever a sure thing. For every solid pitching prospect there are likely 3-4 that fall by the wayside. For Tigers fans everywhere, here’s to hoping that Rick Porcello kid does not fall into the same category as any of these four pitchers.


The Unluckiest April Pitchers

When discussing the early season productivity of a player it is important to remember that the barometric statistics analyzed by those on television often have better evaluative indicators beneath the surface. Many of these indicators deal with luck, or a lack of luck, and provide a more telling window into what should be expected from the player in the coming weeks and months. Dave Cameron wrote earlier today about Nick Johnson and how, based on his high percentage of line drives but low BABIP, Johnson has experienced an unlucky streak this month. Using a slightly expanded method to the ones currently used to determine luck (relative to GB/FB/LD and BABIP) I decided to figure out the unluckiest pitchers of the month.

Initially the method consisted solely of BABIP and the difference between FIP and ERA (FIP-ERA) but I then extended it to include their current W-L records. Though anyone at least casually versed in statistical analysis will explain the faults of a W-L record, fans that simply love the game without analyzing anything equate W-L records to quality.

A pre-requisite also found its way into the criteria in that the FIP could not be above 4.30, a cutoff I usually look for when determining the difference between good and average. This way players like CC Sabathia and Barry Zito could be avoided; players who, despite having large FIP and ERA discrepancies, still had very high FIP and ERA counts. In summation, the players I considered to be the unluckiest were those with high FIP and ERA discrepancies, a high BABIP against, and a W-L record that does not do a good job of representing the quality of games pitched. This left me with the following four candidates:

    Nate Robertson: 6.91 ERA, 4.18 FIP, -2.73 FIP-ERA, .333 BABIP, 0-3 W-L
    Nick Blackburn: 3.45 ERA, 2.72 FIP, -0.73 FIP-ERA, .347 BABIP, 1-1 W-L
    Ian Snell: 4.45 ERA, 3.03 FIP, -1.42 FIP-ERA, .358 BABIP, 2-1 W-L
    Zach Duke: 5.34 ERA, 3.97 FIP, -1.36 FIP-ERA, .369 BABIP, 0-2 W-L

So, of these guys, whom do you consider to be the unluckiest this month?