The Next Step

Let me start theoretical. I wonder why prospect lists run in order of career potential. In my view, prospects are valuable because they provide Major League Baseball’s best bargain. Find a player ready to contribute from Year One to Year Seven, and the return on investment is ridiculous. In three seasons, Tim Lincecum has been worth roughly $84 million to the Giants. If you didn’t know, he has not been paid that much. However, in a few short years, Lincecum will enter free agency, and he will no longer be a bargain. Teams will bid for his services, and he will be paid appropriately by what the market determines.

In my eyes, prospect lists should attempt to determine a ranking based on what value players will provide when they are under organizational control (first six to seven years). If we follow prospects because they are a bargain, we should only care about their performance when they represent a bargain. Right? Consider yesterday’s posterboy, Garry Templeton, who in a retro prospect list, probably wouldn’t rank very highly. But why not? Templeton was well above the average shortstop with the Cardinals, and was the centerpiece of a trade that netted the Cardinals Ozzie Smith. Templeton provided insane value to the Cardinals.

In fact, in their first seven seasons, Garry Templeton produced 20.5 WAR. Ozzie Smith, who peaked in Years 7-12 of his career, produced just 17.7 WAR in his first seven years. Now, readers, I ask you: why would Smith be considered the better prospect in hindsight? Particularly in today’s environment, when loyalty doesn’t exist with free agents.


As I’ve transitioned back into covering minor league baseball, I have begun to see the direction I want my analysis to take — it’s both outlined above, and it exists in the FanGraphs defining stat: WAR. I want to attempt to see prospects in the light that the organizations might: who is overvalued relative to the likely contributions they’ll provide and thus make a nice trade chip, and who should teams be making way for? What value might a prospect provide our team? Eric Hosmer and Pedro Alvarez are right next to each other in Keith Law’s rankings; if each is the player scouts think they could become, what does that look like in terms of WAR (an article for another day?)

This is long-winded, as I so often am, but I’m trying to create a dialogue about what a sabermetric approach to covering prospects can be. And I want your help! It’s no longer about ignoring scouting reports and restricting yourself to MLEs (was it ever?), but about finding the proper routes to evaluating players more accurately — based on development (like yesterday), based on nuance (the sinker series), and based on modern statistical analysis.

Today, I’m going to take a stab at the latter. After the jump, we’ll walk through creating a set of expectations on what the Cubs should anticipate from Starlin Castro (sorry, he’s on the brain).

Note: This will be an assumption that Castro is an everyday player for the Chicago Cubs. Prospect analysis is about balancing the potential for stardom with the potential for bust in your analysis. This is purposely avoiding the bust/bench player route than Castro — and nearly every prospect — could potentially reach.

Starlin Castro, the everyday player, hits in one of three spots in a Major League lineup: second, seventh or eighth. Modern Major League Baseball leaves the possibility of Castro leading off as a longshot, given walk rates that aren’t acceptable. So, I began by averaging together the plate appearances those spots in the lineup had for the Cubs in 2009: 685. Then, I decided to give Castro seven off days for the season. This will be an analysis based on Castro’s production given 655 plate appearances.

Next, you want to create a set of raw counting statistics that will add up to 655 PAs. This means quickly deciding on three different Castro skillsets:

Contact: Castro is fantastic in this regard, and whiffed in just about 10.5% of his plate appearances last season. Given that the number that first came to my head was 75 strikeouts, and that it represents a small increase due to tougher pitchers, I think it’s fair.

Patience: Alomar was one of the only from yesterday’s study to embrace the base on balls, and the Cubs don’t preach patience enough for me to believe Castro will walk much — certainly not until he’s a little older. I have him bookmarked for 40 walks, two of which are intentional.

Power: This is the most important, and with Castro, toughest to project. Jim Callis yesterday suggested he could hit 20 home runs. I don’t see it. If it does happen, like Jose Lopez, it will almost surely be later in his career. If we’re thinking about some six-year average, I’ll use 10 home runs. I’ve added 33 doubles and 7 triples. From there, it’s filling in the blanks.

75 K. 40 BB (2 IBB). 33 2B. 7 3B. 10 HR. 5 HBP. 8 SH. 5 SF. 1 CI. 3 RBOE.

Adding this up, we can say this represents 596 at-bats. I then assigned Castro a .310 BABIP (Jose Reyes‘ career average), and did a little algebra, which determined that this meant he clubbed 170 hits in this mock season, 120 going for singles. I’m projecting Castro at .285/.333/.414, and I admit, this feels right.

Next, I calculated wOBA, using this handy guide. Plug in the numbers, and out comes a .327 wOBA. Rather than take the long route to turn this to wRAA — and so I wouldn’t have to guess league OBP and create a scale — I did something easier. If Reed Johnson posted a 0.2 wRAA in 186 plate appearances, with the same wOBA, then changing the plate appearances to 655 puts Castro’s projected wRAA at 0.7. As you know, our RAR formula here is a simple addition of four numbers: wRAA, UZR, and adjustments for replacement and positional. We can do the replacement pretty simply: 655 plate appearances works out to 22.8 runs above using our formula.

Halfway home, and I currently have Castro’s RAR at 23.5. But, as reader Rob G. noted in the comments yesterday: “Castro’s defense at an important defensive position is much of the reason behind the hype.” Indeed. This was why I restricted myself to middle infielders in yesterday’s comparisons, but if we are set to calculate his WAR, we need a decent guess at UZR. So, here I turn to Kevin Goldstein, who wrote two poignant comments concerning Castro when he ranked the shortstop second in the Cubs system. The Good: “His defensive fundamentals are outstanding for both his level and his age, with smooth actions, soft hands, a quick transfer, and a plus arm.” And, the bad: “Several scouts noted below-average running times to first base, and his range is affected by it, possibly leading to a move to second base down the road.”

This made me think of Elvis Andrus, one of our comparisons from yesterday. What did Goldstein say about his defense, which stood +10.7 as a rookie? “He has outstanding shortstop action, a plus arm, and exceptional range,” Goldstein wrote a year ago. So, Castro and Andrus share the outstanding “actions,” and the plus arm, while Castro comes out ahead in hands, and Andrus definitely in the range column. Now, I’d be cynical to note that Andrus’ plus defensive season entirely consisted of his RngR, but it’s true. I would say that Castro sounds like a zero to +5 defender at shortstop, and a +5 to +10 defender at second, to lean conservatively and stress the importance of range in Ultimate Zone Rating.

I do not think we would be doing Castro a disservice by saying that his positional adjustment and defensive rating were the equivalent of 10 runs above replacement. Consider that Andrus’ position adjustment was only 6.4 in 145 games, so if Castro sticks at shortstop and has a similar adjustment, I’m calling him a true +3.6 defender. That is a compliment.

If you’re still with me (God bless you), then it’s time to add everything up: 33.5 Runs Above Replacement. I’ll leave it to you to determine if this is a conservative estimate or an aggressive one, but I think it’s a nice median expectation. As a Cubs fan, I think this would be great news if it were sustainable — if Castro was a 3 WAR player always. But I’m guessing that is one sentiment that would not be greeted kindly at Clark and Addison.

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Mike Green
Mike Green

It isn’t really a median projection. Castro was 19 years old, and had only 111 at-bats in double A. There is probably a 30% chance that he gets no more than a cup of coffee in the major leagues.

What I would suggest is that you try to get a weighted average using something like this:

0-1 WAR 30%
1-2 WAR 20%
2-3 WAR 25%
3-4 WAR 15%
4-5 WAR 5%
5-6 WAR 4%
Utley 1%