Losing Your Edge in Games Where You Can't Go Broke (and How Successful Teams Start Losing)

Every month, Kyle Boddy releases his/Driveline's internal xERA and Stuff farm system rankings, which have been very informative. The leaders are pretty much who you would expect, it's some version of the Dodgers, Rays, Astros, Yankees, or Baltimore, and some usual suspects like the Royals and Rockies at the bottom. What I find striking is that the A's and the Cardinals are consistently near the bottom of the list. Some teams have been penalized by either promotion or trades (or in the Astros case, forfeiting draft picks), which is not the fault of the organization per say, but the A's and Cardinals do not have this excuse. 

What I find so fascinating about this is that the A's and the Cardinals were at the top of the game in cutting edge analytics. Everyone knows about the A's and Moneyball, and the Cardinals were one of the first teams join the A's in having an analytics based approach. Adopting analytics and being bold was wildly successful for them, as the Cardinals won a couple World Series titles and the A's were very successful despite cheapskate ownership. Now, they seem to have fallen behind by not emphasizing new player development initiatives, which is where the cutting edge of baseball analytics is right now. One example is that Boddy notes how the A's have an extremely fastball heavy approach, which is an old school philosophy that is falling by the wayside. For the Cardinals, drafting Michael McGreevy in the first round feels like a pick that would have been sharp in 2005, but now that we have more than surface level college stats and can look at things such as spin rate and vertical movement, probably is not a great first round pick.

In professional gambling, it's extremely easy to know when you have lost your edge. You lose all your money. In professional baseball, it's not that black and white. In fact, it's super easy to ignore the warning signs by looking at surface level stats and dismissing criticism by saying Twitter isn't real. That's fine. The Cardinals are above .500 and the A's are explicitly rebuilding right now, so from a results based mindset things do not look too bad. This level of apathy can linger for a long time, far longer in comparison to a professional gambler losing his or her edge.

Hopefully both teams can reclaim their boldness and get out of the cellar of minor league xERA. As early adopters, the A's and Cardinals face a problem that many large businesses have the first time they reach growth slumps. It will be interesting to see if they can regain their startup magic.

Setting Informative Priors for Bayesian Mixed Effects Models

 https://rpubs.com/dgerth5/924572

Overoptimizing Drafts

As we head into the 2022 Draft, I have been thinking about draft trends and how different the hot new pitch archetype has changed over the past couple years. Nowadays, you can't scroll through baseball Twitter without someone talking about "sweep," but this was not always the case. A few years ago, pitching Twitter was fired up about guys throwing 4 seamers up in the zone, and having a 12-6 or gyro slider to go along with it. This was a very successful strategy, and still is. However, now that we know how good an east-west pitcher can be and how they can be developed effectively, there is less emphasis on drafting the vertically oriented guy. Passing over a guy with a ton of SSW on his sinker just because he doesn't have a carrying fastball is a bad idea, but the public did not have this data a few years ago and thus overreacted (slightly) on traits that could be measured easily and performed well.

My point in writing out this out is to say optimizing your draft for what is popular now does not guarantee future success. If you did nothing but draft pitchers with rising 4 seam shapes and vertical breaking balls, you would have done fairly well. However, if in the later rounds you were debating between a mediocre present stuff vertical oriented pitcher versus a slightly better present stuff east-west pitcher, and you take the vertical pitcher on the assumption that the prototype is more projectable, that probably was the wrong decision, given how good player development has gotten in developing horizontal stuff. Note that I am not suggesting we go back to the days of drafting guys with 88 MPH generic sinkers. These guys are not good.

The easy part is drafting someone and the hard part is maximizing their development. It is a fair point that if a team was not drafting vertically oriented pitchers, they were not also thinking about sweeping sliders or SSW on a sinker and generally did not know how to develop it. The main lesson is to draft the player, not the prototype. If you draft a player because he fits the in vogue prototype, not because you have faith in his tools or a development plan tailor made for him (and lets face it, most teams don't), you might get lucky and get a solid player, but eventually you will get adverse selected by teams pushing the envelope and drafting players based on what they think the game will be in a few years. It's hard to do this well, but the only way to have a robust drafting and developing strategy.

A Bayesian Comparison of Bond ETF Volatility

Off topic post on bond ETF's and comparing their volatilities:

https://rpubs.com/dgerth5/922557