At this point, it is probably hard to find a single Cardinals fan who wouldn't want Jason Heyward back on the team in 2016 and beyond. After a slow start, Heyward turned things around and put up a phenomenal six win season through a combination of above average offense (121 wRC+), defense (24 defensive runs saved), and baserunning (7 BsR). He was the 11th most valuable position player in baseball this season according to fWAR, and he ranks 11th in fWAR among position players since he first broke into the major leagues in 2010.

Despite these amazing numbers, some have suggested that the Cardinals don't necessarily need Jason Heyward going forward because of the outfielders who are already on the team: Matt Holliday, Randal Grichuk, Stephen Piscotty, and Tommy Pham. (Jon Jay and Peter Bourjos are also under team control for one more year, but their future with the team is unclear.) There are some who believe that Randal Grichuk and Steven Piscotty are both capable of being starting outfielders for the Cardinals going forward, making Heyward a luxury, not a necessity.

Former Cardinals outfielder and current 101 ESPN contributor Chris Duncan made such a claim recently, arguing that the Cardinals shouldn't overpay to keep Heyward because of their other outfield options. Personally, I am not the biggest fan of Duncan's work, and I almost wanted to dismiss his article completely due to the fact that the only statistics he cited were Heyward's home runs and RBIs. With that being said, I think it is important that we play devil's advocate for a moment and consider some of the arguments against signing Heyward.

First, it is true that signing Heyward would mean less playing time for Randal Grichuk and Stephen Piscotty. Heyward and Matt Holliday would presumably be in the lineup on an everyday basis, and Grichuk and Piscotty would be left to share time in the third outfield spot, whether that be in center field or right field. Grichuk and Piscotty both had excellent seasons in 2015, and they received extensive playing time when they were healthy and on the major league roster.

Player PA BB% K% ISO BABIP AVG OBP SLG wRC+ fWAR Randal Grichuk 350 6.3% 31.4% .272 .365 .276 .329 .548 137 3.1 Stephen Piscotty 256 7.8% 21.9% .189 .372 .305 .359 .494 133 1.1

Based on 2015 numbers, it would appear that re-signing Heyward would result in playing time being taken away from two players who deserve to be starting outfielders. This isn't necessarily a bad thing, since Heyward still represents a clear upgrade over both players. When considering Heyward's value to the Cardinals, though, we need to consider his value relative to the value of the player or players he would be taking playing time from. Last offseason, in one of my first posts at VEB, I made a similar a point when looking at why the Cardinals shouldn't sign Max Scherzer. Because the Cardinals already had Carlos Martinez, I didn't believe it made sense to pay top dollar to sign Scherzer, since the marginal upgrade would be three wins at most.

We should value Heyward in a similar fashion, since it appears that signing him would result in less playing time for two players who are above replacement level. Because of the presence of Grichuk and Piscotty, Heyward should have less value to the Cardinals than he would to a team with less appealing outfield options, since the value added would be comparably less. To value Heyward properly, we need to figure out just how much Grichuk and Piscotty will be worth in 2016 and beyond.

Unfortunately, we cannot simply take the 2015 stats of Grichuk and Piscotty and extrapolate them out to a full season's worth of data. Doing so would be ignoring the fact that Grichuk and Piscotty both had unsustainably good season that probably cannot be repeated over a longer stretch of games. A good number to look at when evaluating whether or not a player can sustain his performance going forward is his BABIP, which indicates a player's batted ball success (or luck, if you prefer). In most cases, a player's BABIP will regress towards a mean of around .300 over a longer period of time, and this will usually happen for both underperforming and overperforming players. In 2015, Grichuk and Piscotty posted BABIPs of .365 and .372 respectively, which means they were very fortunate when they put the ball in play. If we want to set reasonable expectations for Grichuk and Piscotty, we have to project their batting line with a BABIP closer to league average, which is the most likely outcome going forward.

Projection systems are very good at doing this in an objective manner, and as it turns out, Steamer projections for 2016 are already available over at FanGraphs. Here is what Steamer projects for Grichuk and Piscotty if they were to receive the playing time of a full-time starter in 2016 (600 plate appearances).

Player BB% K% ISO BABIP AVG OBP SLG wRC+ Def fWAR Randal Grichuk 5.4% 24.6% .197 .294 .248 .294 .444 100 -0.8 2.0 Stephen Piscotty 7.5% 16.8% .140 .304 .267 .327 .407 103 -10.8 1.0

When we take away Grichuk and Piscotty's unusually high BABIPs, they suddenly look much more like league average hitters. Projection systems are not perfect, however, and it is quite possible that these projections are too conservative. I think this is especially true with Piscotty, who is probably a better defender than the metrics give him credit for. These projections are also slow to adapt to his 2015 power surge, which appears to be the result of a deliberate change in approach. (His minor league numbers from before this season factor into his projection.) Even with these adjustments, though, it is probably unreasonable to expect Piscotty to be better than a 2.5 win player.

Interestingly enough, Tommy Pham actually had a slightly better Steamer projection (104 wRC+, 2.3 WAR in 600 plate appearances) than both Grichuk and Piscotty. He should be a factor in the 2016 outfield mix as well, but it might not be reasonable to imagine him as a full-time starter, given his injury history.

While the Cardinals appear to have multiple options capable of taking over in the outfield if Heyward departs in free agency, there is a wide gap between their projected value and Heyward's projected value. Steamer projects Heyward to be worth 4.2 wins in 600 plate appearances, with a .275/.352/.439 batting line and a 118 wRC+. If this win total seems low, it is probably because Steamer expects Heyward to be worth ten runs less on defense and five runs less as a baserunner. Even so, Heyward is at least two wins better than his alternatives, and I would imagine that this total is probably closer to three wins, since there is no reason to expect this drastic of a drastic decline in Heyward's defense and baserunning.

While paying $20 million or more per season for a three win upgrade might not necessarily look like a great move, it is important to note that Matt Holliday may be gone after 2016, opening up another spot in the Cardinals' outfield. The presence of Heyward may mean less playing time for Piscotty and Grichuk in 2016, but this arrangement will probably only last a year at the most.

There are also plenty of ways in which Grichuk and Piscotty could recover some of this lost playing time in 2016. The Cardinals have the option of playing Piscotty at first base as a right-handed complement to Brandon Moss and Matt Adams. They could also choose to give Matt Holliday more time off in 2016, especially given his injury issues in 2015. Holliday's Steamer projection actually only has him being worth 2.1 WAR in 600 plate appearances, which puts him in the same range as Grichuk, Piscotty, and Pham. While Holliday is probably still the best hitter of this group, his defense in left field has regressed significantly in recent years, and his recent quad injury certainly won't help. It will be fascinating to see how Mike Matheny manages Holliday if and when he is no longer the best option in left field for the Cardinals.

The last advantage to having five outfielder capable of starting on an everyday basis is that the team would have quality depth in the event of a significant injury. It is likely, if not inevitable, that one of the Cardinals' outfielders will miss significant time with an injury at some point during the 2016 season, making having quality depth a necessity, not a luxury. And even if the Cardinals' outfielders make it through the season healthy, Mike Matheny will be able to rotate players in and out of the lineup and keep them fresh for the postseason. (It is debatable whether Matheny is capable of managing such an arrangement in an optimal way, but we can be optimistic for the time being.)

The Cardinals will be faced with the task of figuring out how much Jason Heyward is worth to their team going forward. While there may be other capable outfielders on the Cardinals' roster, none of them can come close to matching Heyward's overall value, and their presence should not deter the Cardinals from making a serious push to re-sign him this offseason.