How much better will Detroit Tigers’ defense be in 2015?

Despite winning four consecutive American League Central Division titles, the Detroit Tigers’ defense has left much to be desired over the past few seasons. The Tigers had negative 65 defensive runs saved (DRS) during the 2014 season, ranking 13th of 15 teams in the American League.

Note: There is a glossary for defensive metrics for reference at the end of this article.

Using other measures, the Tigers also ranked 13th in ultimate zone rating (UZR) and revised zone rating (RZR), or the percentage of balls hit into their collective fielders’ zones during the season that are converted into outs. The Tigers were also 13th in making out of zone plays.

While defensive metrics are not an exact science, each of the above measures includes data from over 13,000 innings and over 1,800 balls put in play during the 2014 season, and they all say the same thing. The Tigers’ defense was not very good, and it cost the team runs -- and wins -- during the season. Only two players, Ian Kinsler and Alex Avila, were plus defenders for the Tigers last season.

The good news is that, of all the areas where the Tigers made changes since the end of the 2014 season, defense is the one area where the club is expecting the greatest improvement. Three players are largely responsible for this optimistic outlook.

Jose Iglesias is back after missing an entire season with stress fractures in both of his legs. He will replace the Tigers' shortstops that, collectively, were worth -10 defensive runs saved compared to the American League average in 2014. In two partial seasons at the position prior to last year, Iglesias was worth +7 DRS, and his RZR of .831 ranks third in the league. Insert the obligatory "small sample" disclaimer here, but by every measure, including the eye test, Iglesias should be able to give the team somewhere in the range of 20 to 30 runs saved.

When the Tigers traded Austin Jackson to Seattle in the trade that brought David Price to Detroit, they used a combination of players to fill the void in center field. Jackson’s defense has declined over the past few seasons, leaving him somewhere between league average and eight to 10 runs below average among center fielders. Overall, the Tigers’ center fielders posted defensive numbers of -7 DRS and -8.2 UZR for the 2014 season.

Anthony Gose was acquired from the Toronto Blue Jays in exchange for infield prospect Devon Travis with a reputation for his speed and defensive ability. In just over 900 innings in center field across three seasons in the major leagues, Gose has a +2 DRS, and projected to save 13.6 runs over 150 games using UZR/150. He converted 201 of 213 balls hit into his zone into outs, ranking fifth among 26 center fielders who logged at least 900 innings over the past three seasons. Fangraphs has a cutoff of 900 innings per season for "qualified" fielders.

Rajai Davis will share time in center field with Gose. Davis has played just 522 innings in center field over the past three years. Despite his speed, Davis does not have the reputation of being a plus defender, but the numbers available suggest that he is much better in center field than he is in left field. In his limited playing time in center field from 2012- 2014, Davis has an RZR of .967, with a projected UZR/150 of 12.0. In his career, going back to 2007, Davis has a 0 DRS rating and 0.0 UZR/150 in over 3,500 innings in center field, putting him right at the league average.

Just as the Tigers are uncertain about how well Davis will play in center field, they are also not sure whether Gose will hit well enough to remain in the lineup against right handed pitchers, which is what they will be facing at least 70 percent of the time. Davis mashes left-handed pitching with an OPS of .939 wOBA of .408 in 2014, but posted only a .617 OPS with a .277 wOBA against right-handers.

The initial word from manager Brad Ausmus is that he will not deploy a strict left-right platoon in center field, but rather use Davis against left-handed pitchers and some right-handers. However, if Gose can hit even a little bit against right-handed pitchers -- he posted a .329 on base percentage against them last season -- then he should get the nod.

The Tigers should see some improvement defensively in center field in 2015. Having Gose roaming the spacious grounds at Comerica Park most nights, with Davis picking up the slack, could be worth a dozen runs or so over the course of a season.

Yoenis Cespedes will give the Tigers the single biggest defensive upgrade by replacing the aging Torii Hunter. A nine-time gold glove winner, Hunter had become not only a liability in the field, but Fangraphs rated his defense dead-last among 29 qualified outfielders in the American League for the 2014 season. With a -18 DRS and -18.3 UZR, by any measure, this was a position in dire need of a defensive upgrade.

Cespedes ranked fourth in the American League among all qualified outfielders with a 11.4 UZR/150 and +11 DRS. He did this despite having below average range. All of his plus defensive ability is in his right arm, which rated as the best in the league. Even league average defense would be worth 18 runs to the team during the season, and another dozen runs would push that difference up to 30 runs saved in just one personnel change.

J.D. Martinez rated -1 DRS, while Davis rated -8 DRS in left field last season, with about equal playing time. Although Hunter played right field and Cespedes will be playing in left field, with Martinez moving from left to right, it is easy to see how the two new outfielders could save the Tigers about 40 runs over the course of a full season.

The Tigers’ outfield collectively posted -33 DRS and -35 UZR over 162 games in 2014. The Kansas City Royals led the American league in 2014 with +46 DRS and +59.8 UZR. That gave them an advantage of 80 to 95 runs over Detroit, just due to outfield defense. All four other teams in the AL Central were the four worst teams defensively in the outfield. Detroit is the team that made the necessary moves over the offseason to upgrade their defense.

One other personnel change could have a significant impact on the Tigers’ defense. James McCann is expected to take the place of Bryan Holaday as the back up catcher. With Alex Avila’s health being a concern, McCann figures to start at least 50 to 60 games behind the plate. I asked Jordan Gorosh, who writes for Baseball Prospectus, and Paul Wezner, managing editor of TigsTown, to compare McCann’s defense with Holaday. Here is the exchange.

@TigersProspects How does McCann compare with Holaday, defensively?

— Patrick OKennedy (@Tigerdog_1) February 21, 2015

@Tigerdog_1 better. Holaday is below average.

— TigersProspectReport (@TigersProspects) February 21, 2015

@Tigerdog_1 @TigersProspects McCann is better defensively... Holaday might have a stronger arm tho

— Paul Wezner (@TigsTown) February 21, 2015

With upgrades at shortstop and in the outfield taken care of, the position where the Tigers remain most concerned about defense is at third base, where Nick Castellanos struggled in his rookie season at the hot corner. After being moved back to third base from the outfield and moved up from the minors to the major leagues at the same time, Castellanos posted a -32 DRS, and -18.9 UZR. That was easily the worst in the American League.

The main problem with Castellanos defensively was his range, or lack thereof. His 15 errors -- including only five throwing errors in 145 games -- is not bad, especially for a rookie. But Castellanos’ .587 RZR is dead last among all 63 American League third basemen who have played at least 1,000 innings at third base, going back 15 seasons, to 2000. That number means that 41.3 per cent of all balls hit into the third base zone in 2014 were not converted into outs. The median RZR for the league at third base is .700.

Castellanos answered on his own defense at TigerFest by pointing out the fact that he had not played third base for more than a season and a half before being called up to be the Tigers’ full time starter at the position. The last time that he played third base was in the Florida State League -- against college-aged players -- and he was just 20 years old himself. He is essentially having to learn a new position while starting at the major league level. It is fair to say that some improvement can be expected.

Here is a look at how the Tigers ranked in the American League, defensively, in 2014

How do you think the Tigers will perform, defensively, in 2015?

Glossary:

DRS: Defensive Runs Saved is a measure of total defense, measured in runs saved, used by The Fielding Bible and posted on Fangraphs.

UZR: Ultimate Zone Rating is an advanced defensive metric that uses play-by-play data recorded by Baseball Info Solutions (BIS) to estimate each fielder’s defensive contribution in theoretical runs above or below an average fielder at his position in that player’s league and year.

UZR/150: UZR projected over 150 games, which allows for comparison between players who have played a different amount of time at a given position.

RZR: Revised Zone Rating measures the percentage of balls hit into a player's zone that are converted to outs. The zone is defined as the area where a league average player makes a play at least 50 percent of the time.

OOZ: Out of zone plays are those plays made outside the zone, defined above, which are converted to outs.