Hello, friends, and welcome to a new edition of Everything You Could Have Learned This Week, a tradition unlike any other. I've been on spring break this week, giving me plenty of time to Snapchat pictures of my cats (find me at "ianmcfrazer") and scour the Internet for enlightening baseball writing, so this week's roundup is more robust than ever before. Enjoy!

Nothing is ever quite as good as you think it is, especially recovery rates from Tommy John surgery: Tommy John Surgery Success Rates in the Majors, by Jon Roegele, The Hardball Times

While the numbers are far from complete, it is also worthwhile understanding that of all major league pitchers who had Tommy John surgery in the past five years — who have had one to four seasons to theoretically recover (2010-2013) plus one to four seasons to theoretically contribute (2011-2014), the median contribution has been 29 appearances and 47 innings pitched. So: that mental math you do when it’s announced that a pitcher on your favorite team is having Tommy John surgery, when you picture them contributing at the same level as you’re used to one calendar year from then? It’s not as reliable as you may believe.

Where do pro ballplayers get their gloves? Well, there are some perks to the job: For Pro Players, The Store Comes To Them, by J.J. Cooper, Baseball America

It takes 12 big bags of gloves—arrayed in this case on the lawn at Cubs camp—to make sure that the Cubs’ minor leaguers have a sufficient selection. There are righthanded and lefthanded pitchers gloves in a variety of sizes and colors. The same can be said for outfield gloves and first base mitts, although when it comes to infielders’ gloves, the lefties need not apply. And then there are the catching mitts. There are less of them, but they take more space to pack.

A player's home state and the type of educational institution from which he originated suggests quite a bit about his future trajectory: Geographic Bias in the Amateur Draft: Part 2.1, by Daniel Meyer, Beyond the Box Score

While all other three groups of pitchers start with nearly a 100% chance of reaching the majors at the first overall pick, for high school pitchers from power states the probability is down to 70.6%. However as we move out the probability levels off around 50%. This result could warrant a further study, but I hypothesize that this lower rate of reaching the majors has to do with the high attrition rate for high school pitchers from power states. Due to the higher prevalence of year round pitchers in these states they are simply more likely to blow out their arms before ever sniffing the major leagues.

However, the intense focus on baseball in power states pays off for some of these high school pitchers, leading to pitchers with more refined skills and raw ability. I spoke with a National League area scout who covers parts of Texas who said of high school pitchers, "It’s just different down here." He went on to explain how he’d seen about a half a dozen guys throw 95+ MPH in the past couple of weeks whereas he might have seen one such guy in all of New York. If they can stay healthy, their advanced approach and ability can get them to the majors, hence the leveling off.

Pitchers with more diverse arsenals tend to be less prone to decline late into games: Pitchers Who Play Poker: The In-Game Edge That Mixing Pitches Truly Offers, by Ben Lindbergh, Grantland

Research has shown that this “times through the order” effect — or more accurately, in this case, “times facing hitter” effect — penalizes every pitcher to some degree. Great pitchers the third time through are better than average pitchers the third time through, but only because they start from a higher peak, not because their declines are more gradual. That means that when we’re managing at home (or, in one man’s case, when we’re Matt Williams), we have a mental adjustment to make as the game goes on.

A new variation of war looks at the impacts, both real and potential, of acquisitions and departures: Evaluating Farm Systems and Front Offices: Part 1, by Stephen Shaw, Banished to the Pen

Essentially, eWAR is trying to explain if GMs and front offices are making appropriate decisions about player personnel. I realize this does not work 100% of the time, especially if management has to make decisions based on payroll constraints. For example, not signing Pujols to a long-term contract put St. Louis in a better financial situation. eWAR should be left to evaluating teams based solely on the on-field performance in that year. Also, this is not a predictive statistic, but it can be used as a performance measurement indicator.

Being recently concussed is not good news for a player's offensive production! Surprising, I know: Study Suggests That Hitters' Production Dips After They Return From Concussions, by Nicholas Bakalar, The New York Times

The study identified 66 position players who had concussions between 2007 and 2013, including some who never went on the disabled list. The study then compared their performance in the weeks before and after the injury.

The gap was noticeable. In the two weeks before their injuries, the players hit .249 with a .315 on base percentage and a .393 slugging average. For the two weeks after the injury, their line was .227/.287/.347.

Is it possible, theoretically, to optimize a rotation based on pitchers' home/road splits? Sure. Would the theoretical benefit be of any significant weight? Probably not: Trying To Optimize The Rockies Rotation For Coors Field, by Mike Petriello, Fangraphs

What this does do, with 99% of starts coming on four or five days rest, is tilt de la Rosa and Kendrick in the ways we want them. (De la Rosa has to make one start on three days rest in this scenario, but it’s the final day of the first half, giving him more than a week’s worth of time to recover.) There’s not a single homestand that de la Rosa wouldn’t get a start in, and in eight of the 10 such stretches that last at least six games, he’d get two. If you really wanted to push it, you could give him a second three-days-rest start and have him go three times in the final home stand, by pushing up his Sept. 19 start (when he’ll be on five days rest) a day.

As Rob Arthur has written at BP, part of the reason players over- or undershoot their projections may be found in changes in the way pitchers approach them: Pitcher Respect: A Strange but Effective Way to Project Hitter Performance, by Jesse Wolfersberger, The Hardball Times

You can learn a surprising amount about a hitter by looking at how he’s pitched. Good hitters are thrown fewer fastballs and fewer strikes than worse hitters. Using only pitch-selection variables, it is possible to make a model that describes the quality of the hitter, and does so with surprising accuracy.

Pitchers know the lineup they are facing that day. They plan for each hitter, and make decisions about which ones they can attack and which ones they have to be more careful with. If pitchers are choosing to pitch around or to pitch carefully to Hitter X, the odds are, Hitter X is pretty good.

A big ol' chunk of MLB teams' market valuation comes from their individual stakes in MLB Advanced Media: Why the Nationals are now worth 1.28 billion, by Neil Greenberg, The Washington Post

It has been so successful, estimates suggest it accounted for a one-quarter of the $800 million sale price of the San Deigo Padres in August 2012.

“It is a very lucrative business and stretches beyond just baseball,” said Badenhausen. “They have partnered with HBO and work with ESPN, WWE and valuations have soared to as much as $10 billion for BAM. And every owner owns 1/30th of it. You are not seeing a lot of team sales right now because owners are making money, franchise values are soaring and owners are looking at the value of MLB Advanced Media and recognizing that at some point they are going to be able to cash in on their ownership stake.”

An outfielder's handedness can influence his defensive ability depending on whether he plays left or right field: Gloves out: The Mark Trumbo advantage?, by Ryan P. Morrison, Beyond the Box Score

"Arm Side" is the one that Mark Trumbo would not like — left field for righties, right field for lefties. "Glove Side," left for left and right for right. The fifth column is a new statistic showing the difference in UZR/150 when a player has "the Mark Trumbo Advantage." And yes, what I have listed as "average" for tMTAdv is the mean, not weighted for the length of each player's tenure in the outfield.

The left-handers did superbly as a group: their mean tMTAdv is 5.5 a sizeable improvement but one that gets minimized by the idea that we would expect there to be an improvement, just based on the assumption that the "average" on which UZR is based is a lower threshold in left than in right. And yet, the group of twelve right-handers to have played both positions had a mean tMTAdv of just -0.4 — very close to zero. If we discount the achievement of the lefties, maybe we give the righties some credit for doing about as well despite drawing the short straw.

Carlos Marmol can tell us a lot about the concept of relief pitchers: Why Relievers Get A Free Pass, by Jeff Long, Baseball Prospectus

Over those five seasons relievers walked half a batter more over nine innings than their starting counterparts. While starters averaged a walk rate of 2.7, relievers walked a hitter every third inning en route to posting a 3.2 walk rate. There’s also more volatility within the reliever subset, with the standard deviation for relievers being 1.09, compared to starters who had a standard deviation of just 0.74.

If we revisit the hypothetical in our initial explanations above, we can see that a BB/9 of 3.5 would be pretty bad for a starter (1.1 standard deviations above the mean) but acceptable for a reliever (0.3 standard deviations above the mean). None of this, of course, should be a surprise. Most successful relievers were starters at one time or another. They inevitably find their way to the ‘pen for a multitude of reasons, be it lacking a third pitch, poor command, lack of stamina, or some other issue that prevents them from being a major-league starter. So reality matches our expectations: relievers have worse command and walk more batters. What goes into this being a reality though? That’s much more complicated.