James Shields or Ervin Santana: A difference of $40M

James Shields is the undisputed No. 3 starter of this year's free-agent rotation.

Elite throwers Max Scherzer and Jon Lester sit 1-2 in the market, while Shields has established himself as the best of the rest. If Scherzer and Lester are the $150-million arms of the 2014 class, then Shields is the only $100-million man.

The drop-off from Shields is significant in terms of projected salary, but is it by way of performance?

(Courtesy: FanGraphs)

Ervin Santana is Player A and he projects to land a deal in the neighborhood of four years and $56 million, according to MLB Trade Rumors. Shields: five years, $95 million. While these are well-researched estimations, the market has a mind of its own. 

But assuming the range is correct, that's a sizeable difference considering how similar some of their numbers were the last couple seasons. Is Santana the value buy?

Both pitchers are durable and have recently shared similar K:BB and batted ball rates. Santana's a year younger but has also thrown more pitches. Overall, Shields has been consistently better.

Going all-in on Shields

2015 Age: 33
2015 Projected Steamer WAR: 3.0 (Market Value: $19.5M)
MLBTR Projected FA Contract: 5 years/$95M ($19M AAV)

Shields isn't a bad alternative for teams who strike out on Scherzer or Lester, but he's pitching on the wrong side of his prime and enters his age-33 season having shouldered more innings pitched than anyone over the last four years. 

Valuing his next contract off WAR (which assumes a win is currently worth around $6.5 million) suggests he's a safe bet to earn his keep for another couple seasons, but all bets are off after that.

With the exception of his declining strikeout rate - which could be by design given his fastball velocity was a career-high 93.7 mph last year - there haven't been many red flags in his performance. He's started more games than Lester and Scherzer since 2011 and has the best ERA (3.17) and WHIP (1.15) among the three during that span. 

Shields' run of eight straight 200-inning seasons obviously appeals to most teams, as does his effectiveness against left-handed hitters (slugging .377 versus Shields since 2012).

Settling on Santana

2015 Age: 32
2015 Projected Steamer WAR: 1.7 (Market Value: $11M)
MLBTR Projected FA Contract: 4 years/$56M ($14M AAV)

Santana has put together solid back-to-back seasons after his disastrous 2012, and is averaging 207 innings and 30-plus starts over his last five years. The right-hander might have even produced a better stat line than Shields last year it weren't for a BABIP (Batting Average on Balls in Play) more than 30 points higher than his career average. 

Santana's allowed the second-most home runs in the majors since 2010, but his outlier 2012 campaign (HR/FB rate was over six percent higher than his previous career-high) is partly to blame. The 31-year-old has adjusted his repertoire the last two seasons, relying more heavily on his secondary offerings to positive results. 

His fly ball rate dropped significantly in Kansas City two years ago, and he kept it below league average with a personal-best 32.6 percent for the Atlanta Braves last year.

The Verdict

Shields maintains the individual advantage over Santana, but it may not be worth $30-40 million. There's a case to be made both pitchers are maturing with age and their decline won't be as steep as hard-throwing inning eaters like Justin Verlander.

Santana is better suited in the National League - he pitched to predictably strong results against No. 8 and No. 9 batters in 2014. But the adjustments he made in 2013 with the Royals offers hope his stuff plays in both leagues.

If the contract projections are indeed accurate, a club starved for pitching might consider spending their money on Santana and another inexpensive arm instead of going all-in on Shields.