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An Interview with John Bitzer of Baseball Trade Values

A wide-ranging discussion on the dynamic player valuation environment.

If you are like me, you probably frequently visited the trade simulator on the popular (BTV) in the condensed post-lockout offseason. For fans and analysts looking to game out realistic trade scenarios that factor in constraints like years of contract control, costs, and roster management constraints, there is no better publicly available resource today than BTV.

For those unfamiliar, BTV calculates the expected trade value for more than 2,700 active major and minor league players, offers a trade simulator engine that lets users propose all manner of trade scenarios involving up to three teams, and publishes unique articles and podcasts discussing baseball transactions.

The site offers a high-level explanation of how they model the trade value of players. Fundamental to the three-point calculation (high, median, low) is the concept of “surplus value,” which is simply the estimated on-field value of a player relative to the cost of that player to a team. While the cost of players is often publicly available, calculating the on-field value of a player is significantly more complicated. For that, BTV utilizes now-mainstream concepts like Wins Above Replacement (WAR) combined with future projections, estimates of injury and age-related decline risk, and other adjustments for the economic environment like inflation, years of contract control, positional scarcity, and arbitration salaries.

On the minor league side, BTV relies heavily on the variety of public-facing scouting reports from places like FanGraphs and Baseball America and expands on the excellent research done by Craig Edwards (formerly FanGraphs) and Kevin Creagh and Steve DiMiceli (Point of Pittsburgh) on how to value prospects. BTV then factors in adjustments for positional value (players that can play up the middle defensively tend to be more valuable), injury risk (pitchers are the highest risk), and roster constraints to develop the expected surplus value for hundreds of minor leaguers.

Put it all together and BTV users have the ability to create trade scenarios and get near-instant feedback on whether they are realistic and viable in the real world. Moreover, BTV has become a go-to resource for understanding and evaluating real-life trades and free agent signings shortly after news breaks:

The site’s models have a 94.2% acceptance rate across the more than 300 real-life trades that have occurred since August 2019.

Coming out of the offseason frenzy of trades and free agent signings, I spoke with John Bitzer, founder, and editor of Baseball Trade Values, for a wide-ranging discussion. We covered baseball’s evolving market dynamics, what might be ahead as a result of the new collective bargaining agreement, how the evolving way the game is played might affect things, and how BTV values adjusts to these changes.

Our conversation is below and has been lightly edited for clarity.

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Pitcher List: John, thanks for taking the time to talk with me today. Let’s start with a macro-level question. The economic environment around player valuation has been pretty dynamic since you first launched the site. What have been the biggest adjustments you’ve seen in real-life and how have you adapted the BTV models as a result?

Bitzer: Thanks for having me. A couple of things. One is, that there is a lot of prospect hugging at the very top tier. It’s rare to see a team trade their top prospects. Look back at all the trades the Padres have made the past few years. They have not moved their top guys. Not C.J. Abrams, MacKenzie Gore, or Robert Hassell. They’ve typically moved prospects from the tiers below that. Other teams have been doing that as well. It makes sense, those are their most probable future stars at a cheap cost in terms of salary.

Second, starting pitchers more recently. We started with an assumption that starting pitchers were the most expensive in terms of dollars per WAR a couple of years ago. That’s changed a little bit. This winter we were a little high on Sean Manaea, Sonny Gray, and a couple of others. Now we’re realizing there is a bit of a sliding scale. Aces will always go for a premium because demand for them is high and supply is low. But your #2 and #3 starting pitchers tend to align with the average dollars/WAR that we expect. The back-end starter market has a more plentiful supply, so they become more pliable and fungible in terms of costs. We’ve had to adjust for that.

Pitcher List: On your site, you say you use roughly $9-million per WAR on average. To your point in the first question, there is research by Edwards and others in recent years that indicate free-agent market values have not been linear. How do you account for something like in your valuations?

Bitzer: It’s like a hyperbolic curve. The middle of the curve looks linear, but at the top of the market it flattens out because there is only so much in terms of free-agent dollars that teams will be willing to pay. Mike Trout in his prime was the perfect example. In theory, he was worth something like $70-plus-million per year, but he was only getting paid $36-million because no one was going to pay what he was really worth. So he was actually underpaid for his value, despite the fact that he was being paid top of the market dollars. That’s partly why they had to extend his contract out so long.

Then, at the bottom of the market, you can see the 1-ish WAR players, close to replacement level, and they might be a little overpaid. They are probably replaceable by guys getting paid the minimum salary, so you see them getting designated for assignment and waived when their salaries start to outpace their expected on-field production.

The middle of the curve is pretty linear with the expected dollars per WAR and sticks to that curve pretty well.

Pitcher List: We’ve seen those tier differences and the idea of replaceability at the bottom play out in the off-season non-tender decisions the past couple of years.

Bitzer: To that point, we can see those guys that are entering the more expensive arbitration years, if the player is going to get paid a little bit more than their projection says they will provide on the field, it does not make sense for teams like the Rays, Guardians, or Twins to keep them. We’ve seen that with C.J. Cron and Eddie Rosario, as examples. They were projected to make a little more than they were worth. And the teams thought they were replaceable.

One more thing that brings up is the pretty dramatic de-valuation of second base defense. Take when Kolten Wong’s option was declined for example. Here’s a 2- to 3-WAR player, but the market showed the value of defense at that position was not as important as an offensive profile. The rise of the shift has enabled teams to just put a bat at second base and not worry as much about the defense there, so we had to adjust how we were valuing second basemen.

Pitcher List: How do you expect the ban on shifts to affect valuations going forward? You wrote about this a bit in your article summarizing the CBA impacts. We’ve seen some “position-less” hitters still do pretty well in free agency because shifts and positioning can make their defense passable.

Bitzer: The biggest thing should be a normalization of second basemen that can decently defend and we should see a correction to increase the value of that defense. We would think Wong’s value should increase. But we don’t anticipate that it will be too much or get all the way back to it was. Teams will still value the bat at certain positions like second base and get away with as much as they can within the shifting rules.

The other thing is that we’d think the Joey Gallo, three true outcomes-types, who have been trying to hit it over the second baseman or just hit it out of the park all the time, will see the defense open up a bit and have their batting averages go up a little bit. We can’t know in advance, but we will watch it closely. If we start to see the three true outcomes types or glove-first second basemen getting premiums at the trade deadline, that will be an indicator of teams anticipating and thinking about those changes.

We follow the data rather than anticipate those kinds of things. So, we’ll wait to see what happens before we change our valuations. We’d rather be a little bit wrong following the data than being a lot wrong by guessing ahead of time.

Pitcher List: Let’s talk about getting it wrong. You tweeted after the Manaea trade to San Diego that the majority of real-life deals that your model has not agreed with have come from Padres’ general manager A.J. Preller. Are there any consistent themes with his deals that can explain that?

Bitzer: There are a couple of things about Preller. A couple of years ago he had the top farm system in baseball and a roster crunch. And everyone knew it. So he overpaid to shift into contention mode – the trade for Austin Nola is the flagship example. Everyone knew he would overpay with quantity, so teams were lowballing there. The same thing happened with Manaea and the Athletics this winter. Everyone knew they were moving pieces for a firesale, so they lowballed. That’s a market factor that plays into this.

Part of the explanation for the Manaea trade looking like an underpay by San Diego is that we were a little high on Manaea, a starting pitcher, as I mentioned before, and maybe a little low on the main prospect going back to Oakland, Euribiel Angeles, who Eric Longenhagen of FanGraphs reports has a fantastic hit tool that might be valued higher by pro models than traditional scouts.

What we’re trying to do with BTV is build a model that works in the aggregate. We’ll have exceptions here and there because we can’t model every situation. We’re okay missing some of those specific situations. We aren’t trying to be perfect. We just want to be as close as possible. We’re trying to mimic what front offices do by cobbling together as much of the public information as we can, without having access to any of the proprietary information they have.

Pitcher List: Aside from specific General Managers, what other factors most often cause disagreement between your models and real-life transactions?

Bitzer: Prospects are higher variance. Major League veterans have a longer track record and are more clear-cut in terms of what to expect going forward. The Sonny Gray trade for Chase Petty is a good example. That trade was off in our model. But, the Reds really liked Petty and ignored the history of high school pitchers having that very high bust risk. They wanted that upside and valued it more than the risk.

Pitcher List: The Reds have established a bit of a tendency to be willing to take that kind of risk on raw, hard-throwing prospect pitchers. Does BTV factor team-specific tendencies into the modeling?

Bitzer: No, because we cannot predict where a guy is going to go in a trade. That would be a more sophisticated game theory approach to the scenarios.

Pitcher List: Are there teams that seem to consistently value players in ways that deviate from your models?

Bitzer: Not really. I’ll hedge about the Rockies, though, because they are clearly the least analytical team right now. Their actions have made that clear. They are going to do their own, more old-school thing and don’t seem to follow the models at all now. I have theorized that they see themselves more as an entertainment business than trying to run an efficient baseball team, so they are more willing to do things like overpaying for Kris Bryant to attract fans. But some of their smaller deals have been fine. Randal Grichuk for Raimel Tapia was fine.

Having said that, the previous GM Jeff Bridich seemed to be closer to what we would have expected. Our models actually agreed with the Nolan Arenado trade. We had him at minus-$44-million in trade value because of where he was on the aging curve, his recent performance, starting his decline phase, but was still being paid top dollar. He was a negative value and was not going to opt out because he would not have gotten a better deal on the open market.

Pitcher List: Maybe related to age, let’s switch to making adjustments for injury risk. Can you expand on how that works in the model?

Bitzer: We estimate that risk. There is a typical aging curve for performance that most are more familiar with. That kind of thing applies to injuries as well. The older you are, the more likely you are to get injured and previous injuries will have a tendency not to go away. Nagging injuries never truly really go away as you get older. That can change the valuations. Individual players can still defy that, but it’s not the median expected outcome.

So, it depresses the overall value. We think about the value as a range, although people tend to gravitate to the middle number. We discount for injury, but we are not doctors. There is a really good newsletter by Will Carroll, formerly of Baseball Prospectus, called Under The Knife that covers injuries and what to expect from them. We use and recommend that as a general guide for injuries in our models. At first, it was a bit of trial and error, but we’ve started to trust it more as it’s normalized.

One other point that is related back to the dollars-to-WAR ratio. With inflation, we actually start with the assumption that the dollar to WAR is about $9.5-million. But it ends up being about $8-million on average after we factor in the injury risk.

Pitcher List: On the topic of adjustments, let me go back to the starting pitcher discussion we were having earlier. How have you adjusted for the blurring lines between starting pitchers and relief pitchers?

Bitzer: It’s a really good question. Starting to be more of a blending. The Rays led that charge. When we first started, it was a clearer distinction between starters and relievers, but they are converging. But there are still clear distinctions, like Craig Kimbrel as a closer. After that, then there is a lot of fungibility and the trend of starters going shorter and then starting the parade of relievers. For the most part, though, that’s baked into our projections, so it solves itself in the models to some degree.

We have noticed there is a quality versus quantity difference in terms of market value. It seems that the guys who put up their value through a higher volume of innings are not as valued as guys who put up their value through higher quality innings.

Pitcher List: One more question on adjustments to wrap this up. How frequently do you update your valuations and how reactive are those updates to recent data?

Bitzer: During the season, we have usually updated once a month. But we have sped up the back end of the model and are planning to update twice a month now, especially as we get closer to the trade deadline. Trade values are always changing during the season.

During the offseason, we do an early update and then usually one update after we get some data on the actual activity. And with the prospects, we’ll update those whenever there are big updates to the public reports.

In terms of how recent performance or a breakout impacts the numbers, we start with a three-year baseline for established major leaguers. If they deviate from that, it will start to show up in the early season updates a little bit and then get stronger as we get more data about the change. One exception to that is relief pitchers because they are so volatile. We know teams are making decisions on them based on short-term results.


Thanks to John Bitzer for taking the time to discuss these questions and for creating the Baseball Trade Values resource.


Photo by Jason Rosewell/Unsplash | Adapted by Ethan Kaplan (@DJFreddie10 on Twitter and @EthanMKaplanImages on Instagram)

John Foley

John is a writer for Pitcher List with an emphasis on data and analysis. He is a lifelong Minnesota Twins fan and former college pitcher who believes 2-0 is a changeup count.

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