Wednesday, February 27, 2008

Second-Half Performances: Trend or Mirage?

Baseball players frequently put up numbers during the second half of a season that differ dramatically from what they were able to do in the first half. This can be attributed to a variety of factors. Sometimes it is a player who is young, or returning from injury, and improving as he adjusts to the level of competition. In other instances, we find the opposite affect -- that a player's performance will decline in the latter part of the season as opponents discover his weaknesses and adjust to his style of play. And of course, in some cases, the change in production is attributable simply to luck, or to a particularly good or bad stretch of play.

Whatever the case, oftentimes we can look at a player's second half and use it as a predictor as to how he will perform in the next season. It makes intuitive sense that a player is more likely to carry his performance from the latter half a season forward, rather than the early part of the season. With this in mind, let's take a look at some Twins players who saw their performance rise or fall in the second half of 2007, and judge whether or not we can expect those second-half trends to carry over into the 2008 season.

1. PAT NESHEK, RP
First half: 42.1 IP, 1.70 ERA, 52 K/13 BB, opp .129/.205/.243
Second half: 28 IP, 4.82 ERA, 22 K/14 BB, opp .260/.347/.440


MIRAGE

Neshek's drop-off in the second half last season was dramatic, and I'd be lying if I said I wasn't somewhat concerned. However, for the time being, I am inclined to label it as a mirage. Before being shut down mid-way through September, Neshek had appeared in a total of 74 games last year. That is a ton for a guy whose previous high for an entire season was 65 (set the previous year). While his innings load (70 1/3) was not that bad, it wears a pitcher down to warm up and enter games that frequently, and indeed Neshek was shelved with two weeks left because his arm had worn down. More than likely, that's why we saw his numbers drop off after the All-Star break. He enters this season with a fresh arm after a winter of rest, and hopefully Ron Gardenhire will be a little less liberal about forcing Neshek to warm up and enter games several nights in a row just to get an out or two.

2. JASON KUBEL, OF
First half: 240 AB, .250/.302/.404, 7 HR, 37 RBI
Second half: 178 AB, .303/.379/.511, 6 HR, 28 RBI

TREND

Kubel seemed out of his element for much of 2006 after missing the entire 2005 campaign in the aftermath of major knee surgery. His struggles carried over into the early part of the 2007 season, where he appeared tentative at the plate and seemed to struggle with his pitch recognition. However, even during the hard times, Kubel always made hard contact, and as he began to regain the plate discipline that he showed throughout the minors, his numbers began to improve rapidly. Prior to the All-Star break last year, Kubel's K/BB ratio was 2.6; afterward, that number dropped to 1.4. The latter number is much more in line with his minor-league K/BB ratio of 1.1, and as such it should be no surprise that his second-half hitting line was extremely similar to this career hitting line in the minors of .320/.385/.499. Expect similar things in 2008.

3. MATT GUERRIER, RP
First half: 53 IP, 1.70 ERA, 37 K/13 BB, opp .183/.246/.253
Second half: 35 IP, 3.34 ERA, 31 K/8 BB, opp .272/.318/.463

TREND

Guerrier has always been a pretty solid pitcher, but I don't think there's really any question that he was playing way over his head in the first half last year. His luck evened out in the second half, when his ERA and opponents' OPS shot way up despite the fact that he improved his strikeout rate considerably and maintained a relatively modest walk rate. Considering his past performance and his age, I think it's much more realistic to expect an ERA around 3.34 than around 1.70 from Guerrier. Fortunately, that's still very solid.

4. JUSTIN MORNEAU, 1B
First half: 322 AB, .295/.364/.581, 24 HR, 74 RBI
Second half: 268 AB, .243/.318/.384, 7 HR, 37 RBI

MIRAGE

Through the first four months or so of the 2007 season, Morneau continued to post numbers very similar to the ones he racked up during his MVP campaign in 2006. Then, in August and September, Morneau completely fell apart. After hammering 28 home runs through the end of July, Morneau managed a measly three home runs during the season's final 56 games. The drop-off in power isn't completely shocking, since we saw the same trend even during his magnificent '06 campaign (albeit to a much lesser degree), but in 2007 Morneau lacked a .342 second-half batting average to offset the power outage. His offensive numbers down the stretch last year were dreadful, and it seems completely inexplicable. As far as I'm aware, he had no major injuries, and the drop-off in production did not come along with a noticeable increase in strikeouts or decrease in walks. With all these facts in mind, I'm inclined to pass off Morneau's dud second half as a really bad two-month stretch, rather than a fundamental decline in ability. Considering the massive contract he recently signed, we'd better hope that is the case.

9 comments:

Anonymous said...

Here's the deal with Neshek: from July 13th to July 19th, he was beaten like a rented mule, appearing in 6 games in 7 days. At that point in the season, he had a 1.49 ERA and a .443 OPS against.

Over the rest of the season, he had a 6.14 ERA and an .881 OPS against.

So I'm a little worried that Neshek hurt something in that stretch (I mean, seriously, who pitches 6 times in 7 days?) and that it could come back to haunt him. Maybe not at the beginning of the season, but if something goes pop in that elbow, I won't be surprised.

Re: Guerrier. I think you're right on. I'd kind of like to see him return to his role from 2006, but we'll have to see how Rincon and Crain look, I guess.

Re: Morneau. I read something the other day about some back troubles he had down the stretch last season. That's kind of worrisome if it was the case (they really can't get off that turf fast enough) but hopefully it was just a one-time thing. Morneau had such a dreadful second half last year that it would really be surprising if he was healthy during that stretch.

TT said...

Good analysis.

Neshek is probably the biggest worry here. Its likely he was worn out, but its also likely batters got more comfortable with his unusual delivery. This year will be the test for how good Neshek really is.

Its also not clear from the numbers you provide whether Guerrier struck out batters more often in the second half, or that batters were getting more of the ball when they connected. Either way, he got a higher percentage of his outs from strikeouts.

Since he gave up 7 home runs while facing 148 batters in the second half, while only giving up 2 home runs while facing 203 batters in the first half, it appears to be a little of both.

The difference in the rate he struck out batters was not significant. If he had faced the same number of batters the second half and struck them out at the same rate he would have had 41 K's compared to 37. That difference is just statistical noise.

Anonymous said...

I was just coming here to write about how Neshek was abused, but ubes beat me to it. It was absolutely ridiculous how Gardentool used Neshek. I've always thought that one of Hoser's strengths was managing his bullpen, but that was simply foolish. Hopefully, the kid isn't hurt to the point where his long term effectiveness and earning power has been diminished by that dim bulb approach.

Nick N. said...

Its also not clear from the numbers you provide whether Guerrier struck out batters more often in the second half

Sure it is. In the first half, he struck out 37 batters in 53 innings (6.2 K/9) and in the second half he struck out 31 batters in 35 innings (8.0 K/9). You can argue that it's a fairly small increase over a small number of innings (and you'd have a fair point), but the point is that he was still missing bats.

Ross Williams said...
This comment has been removed by the author.
TT said...

Sure it is. In the first half, he struck out 37 batters in 53 innings (6.2 K/9) and in the second half he struck out 31 batters in 35 innings (8.0 K/9).

I think you missed my point. IP measures how many outs he made, not how many batters he faced. He "missed bats" at almost exactly the same rate over the second half. Its what happened when the batters didn't miss that changed.

John said...

Nice job Nick.

I'm also worried about Neshek. Hardy is great at developing a bullpen, but he can frag their arms. I can't help but think of Romero, who was ridden hard in2002, deteriorated late, and was never really the same.

Nick N. said...

I think you missed my point. IP measures how many outs he made, not how many batters he faced. He "missed bats" at almost exactly the same rate over the second half. Its what happened when the batters didn't miss that changed.

Ah, I see where you're coming from now. Good point.

I can't help but think of Romero, who was ridden hard in2002, deteriorated late, and was never really the same.

Good comp. Let's pray Neshek doesn't go down that road.

Anonymous said...

I'm worried about Neshek but holy crap am I excited for Kubel. Last year at this time I was too and was very disappointed early but the second half really gives me hope. Most already know this but just go look at his minor league numbers and try not to salivate.