Scouting the Centerfielders - Part 1

*added 12/14/2005 by Scott Barzilla*

Willy Taveras has been in the news lately as a rumored bargaining chip with the Yankees and Diamondbacks. Supposedly, Taveras was the principle person involved in a rumor involving Javier Vazquez. This poses the question of whether the Astros should consider trading Taveras. There are two schools of thought on this: he will get only better from here and he will only get worse from here.

In order to determine whether the Astros should consider dealing him, we'll look at those two proposals through fielding and hitting. With the fielding we will look at three dimensions of fielding numbers. Ideally, all three dimensions will show the same thing, but when they don't we will have to look at why and make a determination.

Opportunity Dimension

This is the simplest dimension. This is where we look at putouts and assists to see where Taveras ranks. Putouts and assists are similar to RBIs and runs scored in the sense that they can give us some definition, but depend greatly on the amount of opportunities the fielder has to make plays.

Games Putouts RangeRandy Winn 151 410 2.74 Brady Clark 145 399 2.79 Johnny Damon 147 394 2.71 Aaron Rowand 157 388 2.49 Jeremy Reed 137 383 2.85 Carlos Beltran 150 378 2.55 Grady Sizemore 155 373 2.43 Andruw Jones 159 365 2.36 Carl Crawford 154 361 2.36 Vernon Wells 155 351 2.34 Juan Pierre 160 332 2.12Willy Taveras 148 332 2.31Jim Edmonds 139 318 2.32 Gary Mathews Jr.123 316 2.63 Brad Wilkerson 129 312 2.47 David Dejesus 119 306 2.63 Luis Matos 120 298 2.54 Mark Kotsay 137 298 2.23 Nook Logan 123 282 2.32 Steve Finley 104 266 2.61 Corey Patterson 122 239 2.01 Bernie Williams 112 226 2.07

So, Willy is essentially near the middle of the pack in putouts, but near the bottom of the pack in range factor (total chances per game). Now, we could stop here, but it would be like saying the league leader in RBIs was the best hitter in the league. There are a couple of numbers that can help explain why this is happening. First, the Astros are a high strikeout staff, and their pitchers have a higher groundball/flyball ratio than most of the league.

G/FRoger Clemens 1.41 Andy Pettitte 1.62 Roy Oswalt 1.45 Brandon Backe 1.03 Wandy Rodriguez 1.34 Ezekiel Astacio 0.77

Most of the starters have groundball/flyball ratios well above one to one. Ironically, Astacio has the worst ratio and he had the worst batting average on balls in play, but that's just an aside. The pitchers with the most innings (Clemens, Pettitte, and Oswalt) all had ratios well above the league average. That meant that he didn't get as many opportunities.

SO SO/9Houston Astros 1164 7.26 National League 1052 6.57

So, every fielder had nearly one fewer opportunity (collectively) per game because of the high strike out rates of the pitchers. This is a good thing, but it's not a good thing when we consider only the opportunity dimension. Most of the Astros probably don't measure up in this category because of this. We have to remember that some teams obviously finish as far below average as the Astros do above average. Only two other teams finished with more strikeouts than the Astros, so we can see how skewed the numbers can look. This means we have to find another way.

Efficiency Dimension

STATS Inc. developed a new metric several years ago called zone rating. Zone rating was designed to solve many of the problems associated with range factor. Range factor is based on opportunities while zone rating calculates the percentage of balls a fielder successfully fields that go into his zone. Therefore, it doesn't matter how many opportunities a player gets in zone rating. It only matters what percentage of balls you get to. Zone rating does have one limitation: it cannot measure value, but we'll get to that later. For the time being, we need to see whether the efficiency dimension and opportunity dimensions square up. If they do, then the numbers will likely reveal the truth. If not, then we'll need to go through some more explanation.

Zone RatingJeremy Reed .943 Aaron Rowand .939 David Dejesus .923 Vernon Wells .911 Luis Matos .909 Grady Sizemore .908 Nook Logan .904 Corey Patterson .900 Brady Clark .892 Jim Edmonds .888 Carlos Beltran .887 Juan Pierre .882 Preston Wilson .878 Dave Roberts .875 Johnny Damon .874 Andruw Jones .873Willy Taveras .864Bernie Williams .862 Mark Kotsay .850 Ken Griffey Jr. .802

So, Willy finished 17th in zone rating and 17th in range factor among the twenty centerfielders to play in 100 or more games. That doesn't bode well for his defensive value. However, as we can see, these percentages look nice, but they don't mean a whole lot to us. This is where the value dimension comes in.

Value Dimension

The value dimension is the most important dimension because this is where we convert the opportunity dimension and efficiency dimension into something we can use. Baseball has several units of measurement (outs, runs, and wins), but for fielding, runs is the most important dimension. The good folks at Baseball Prospectus have developed two metrics we will use to measure value. Fielding runs above replacement is a measure of the number of fielding runs a fielder has over the worst possible regular at that position.

Fielding runs above replacement is a good metric we can use to measure productivity. Since Willy T played in nearly 150 games last season, he'll likely finish pretty high in FRAR. Fielding runs above average is exactly what it sounds like. It is what we use to determine value. Both are based on the number of plays that are made, but the formula also factors out discrepancies between groundball/flyball ratios, strikeouts, lefty/righty breakdowns, and ballpark peculiarities. Baseball Prospectus's exact formulas are not available, but they seem to be more accurate than fielding run formulas of the past. The good news is that we don't need to rank the centerfielders since the benchmark is based on an average.

FRAR FRAAWilly Taveras 31 15

So, obviously the value numbers show something that the others do not. Clearly though, the discrepancy means we need to do some debriefing. We discovered that fielders have fewer opportunities in Houston because of the strikeouts and the outfielders have fewer opportunities because of the groundball/flyball ratio. The zone rating is difficult to explain definitely, but when we watch Taveras we notice he sometimes doesn't get a good jump on balls. The question is whether this will improve or not.