Enjoyable with WAR Math | FanGraphs Baseball

How a lot WAR does FanGraphs challenge Ronald Acuña Jr. for in 2026? It’s a extremely easy query. It ought to be particularly easy now that every one of our projections are out. But because it seems, it’s much less clear minimize than it sounds at first, and clarifying it has two advantages. First, it’ll enable you to higher perceive our projections. Second, it’s enjoyable to play with math. So buckle up: We’re doing arithmetic.

First, let’s choose what the “FanGraphs projection” even is. Here’s the related part of Acuña participant web page:

Eight projections, every with tons of numbers. That’s loads! But once I say the “FanGraphs projection,” I’m referring to the primary inexperienced row, the FanGraphs Depth Charts projection or FGDC. That’s the top-line projection we use wherever on the web site that pulls in projections to make predictions. When you see “2026 (Proj),” it’s utilizing that quantity until in any other case acknowledged.

That’s settled then, proper? We’re projecting Acuña for five.4 WAR. Why did I’ve to waste your time with an article about it? It has to do with how we make that projection, a course of you’re about to find out about, most likely in additional element than you needed.

Projection techniques are, at their core, fairly easy issues. They would possibly get there in sophisticated methods, however they’re all attempting to guess how good at baseball a given participant goes to be sooner or later, and so they all strive to try this by predicting the outcomes that that participant goes to accrue on the sphere. If you could have a projection system, you could have projections for homers, singles, strikeouts, walks, stolen bases, and so forth, in addition to a projection for plate appearances, so that you by definition even have a per-plate look projection for every of these statistics.

We don’t use a single mannequin in our official FGDC projections. We take a 50/50 mix of the per-plate look projections from ZiPS and Steamer. Those projections work very well! I’m not going to enter the specifics of validation right here, however multi-model predictions constructed from good fashions are likely to work nicely, and that’s what we use. The fee statistic projections we spit out are nearly as good as we will probably get them, no less than in our estimation. We discard the enjoying time projections from ZiPS and Steamer, although, as a result of we now have a separate course of for projecting enjoying time.

Going from that blended fee statistic projection to the numbers you see on the web site requires a superb enjoying time estimate. Luckily, that’s what Jason Martinez and Jon Becker do at RosterResource. They challenge enjoying time for everybody in baseball; we multiply that enjoying time by the per-plate look outcomes, and that provides us a projected batting line. It additionally provides us projected baserunning and protection, to not point out all of the related metrics for pitchers, however for immediately’s instance, we’ll be specializing in Acuña’s batting statistics. You can think about the identical course of enjoying out in each side of WAR.

How does the RosterResource crew assign enjoying time? They fill out every roster with their finest guess of what that crew’s enjoying time will seem like. They don’t forecast accidents – how may they? Our depth chart projections seem like a depth chart, naturally sufficient. The starter on the depth chart is projected for a full-time function. That’s simply how it’s.

This makes good logical sense, although it’d take a second to wrap your head round. Why not attempt to challenge the imply final result, with some probability of harm? Mostly as a result of that’s not what persons are really on the lookout for in projections. “How many home runs do you project Aaron Judge to hit this year?” inherently assumes a wholesome season. “Only 15, because I project him to get hurt on May 7” can be a extremely unusual reply to that query. If you’re questioning what an on a regular basis participant’s projection appears to be like like, “in a full season” is an unstated norm. The solely exception to this rule is a sound one: at present injured gamers see their enjoying time decreased by the estimated time it is going to take them to return from harm. Zack Wheeler, for instance, is down for 127 innings this 12 months, as a result of he received’t be prepared for Opening Day. For at present wholesome gamers, although, we assume continued well being.

Take Acuña’s projection, for instance. He’s averaged just below 500 plate appearances per full season thus far, with a number of catastrophic accidents slowing him down. If he reaches his FGDC projected 651 plate appearances, it might be the third-most he’s taken in his profession. But we’re not attempting to guess how nicely Acuña’s knee would possibly maintain up in our preseason projection. We’re projecting what he’ll seem like if he performs a full season. That’s what individuals need, in my estimation, the factor they’re really asking for. Maybe not each particular person. But within the combination, I feel that’s clearly the most typical use case for a projection system, essentially the most truthful strategy to reply the query of how good a man goes be, which is what these fashions had been constructed to deal with.

If you’ll permit me a quick playoff odds tangent, I’ve really spent a great deal of time occupied with how this technique interprets to odds projections. And over-allocating enjoying time to the highest gamers on this method nonetheless works nicely in our playoff odds mannequin. We simply add up the person contributions of each participant on a crew to determine how a crew tasks to play, then toss these outcomes into the BaseRuns formulation, which does a superb job of turning team-level outcomes into run scoring estimates. Sure, projecting Acuña for 651 plate appearances is a little bit optimistic, however we’re symmetrically optimistic. We have Mike Trout down for his most video games since 2019. We have Alex Bregman down for 679 plate appearances, a quantity he’s solely hit as soon as within the 2020s. This is a function, not a bug: We challenge groups at full energy within the FGDC numbers. That playoff odds mannequin isn’t even WAR (nicely, the WAR-based odds mannequin is, however that’s a narrative for one more day). It works completely nicely merely by final result statistics.

Our odds already deal with in-season accidents rapidly; if a participant will get damage, their enjoying time declines to replicate that harm. We’ve additionally experimented with accounting for depth and probability of harm in our playoff odds. That technique feels promising, and I’ll have extra on it as we get nearer to the season. But that’s a small adjustment to an already-good mannequin. The present playoff odds mannequin already handles the optimistic enjoying time allocation nicely, one thing we’ve examined on a number of events.

Alright, let’s get again to WAR. The FGDC projections for dwelling runs, singles, and the like are an awesome estimate of what Acuña’s statistical outcomes will seem like if he performs a full season, of that I’m certain. But WAR isn’t an on-field statistic. It’s a derived statistic we add later that relates a participant’s contributions to what a replacement-level participant would do. During the season, that is easy to calculate. We take precise outcomes and use them to outline alternative stage. Everyone’s efficiency will get measured relative to that league-wide alternative stage. The system works in the best way you’d count on. It reduces all of the completely different dimensions of efficiency right into a single forex of runs, compares these runs to a baseline set by league-wide manufacturing, and turns these inputs into WAR.

Projection techniques don’t have that luxurious. They don’t know what the league common outcomes will probably be in 2026. They challenge a WAR determine, in fact, however that’s relative to a baseline that they calculate of their fashions, based mostly on how that exact system handles enjoying time allocation. It’s solely pure: To calculate wins above alternative, you need to know alternative.

At the person mannequin stage, that’s nice. But we’re not utilizing a person mannequin. We combination fashions at a per-plate look stage after which assign our personal completely different enjoying time, which is usually meaningfully completely different than what both Steamer or ZiPS used. Again, we try this on objective. We achieve this as a result of it helps create team-level projections the best way we would like, and helps reply the “What would this player look like in a full season?” query that almost all everyone seems to be asking.

How completely different would the scoring surroundings be if each star performed as incessantly as our Depth Charts enjoying time suggests? Let’s cease for an instance. Think concerning the main league hitters who performed in 2024 and in addition in 2025. If you’re taking their 2024 outcomes and weight them by their 2025 enjoying time, you get a .311 wOBA. In different phrases, the expertise stage of the gamers who performed in 2024 and 2025, in 2024 phrases, is a .311 wOBA.

Try that once more with our Depth Charts projections for 2026, and also you’ll get one thing completely different. The expertise stage of the gamers who we’re projecting to look in 2026 – their 2025 wOBA weighted by their 2026 enjoying time – comes out to a .316 mark. That’s a significant distinction, although it sounds small. Over 600 plate appearances, that’s an additional three or so runs. Over the 193,000 or so plate appearances that the gamers getting back from 2025 to 2026 are projected to accrue, it’s extra like 800 runs. In our hypothetical 2026 world, the one which we construct by taking fee statistics from the fashions and including our personal enjoying time, the offenses are all good.

The pitching staffs are all good too, in fact. But our Depth Charts rendition of expertise doesn’t measure this interplay. The hitters are projected to be actually good, as a result of their projections are towards a decrease baseline. The pitchers are additionally projected to be actually good, as a result of we do the identical type of over-allocation of enjoying time to stars on that facet of the ball. But since we simply take Steamer and ZiPS fee statistics reasonably than doing a little type of adjustment for opposition on our finish, we don’t dock any batters for his or her anticipated more durable competitors. The result’s a type of Lake Weobegone projection: We suppose that each batters and pitchers will probably be above common in 2026.

That sounds fairly bizarre, however it’s not an issue relating to projecting the season. When we run our playoff odds, we take crew runs scored and runs allowed estimates produced by our depth charts, flip that right into a profitable share, and thus get a measure of crew energy that doesn’t account for opposition. To simulate a recreation, we simply examine the crew strengths of the 2 groups enjoying. Since everyone seems to be over-estimated and we’re solely evaluating groups comparatively, the projections nonetheless work correctly. We is perhaps projecting a way more gifted league in 2026 than in 2025, however there aren’t any further wins to go round on the finish of the day, and since we’re measuring everybody relative to their opposition, it simply works.

There’s some bizarre math stuff right here that you need to maintain in your head. There’s no means that every one of our WAR projections may be proper. It’s actually unattainable. There’s a set quantity of WAR to go round yearly. We have our hitters down for greater than that. If we’re really proper about enjoying time, the baseline stage will merely be increased, and the identical quantity of offensive contribution will simply be value fewer wins above alternative.

Why then don’t we simply modify the alternative stage baseline up in our FGDC projections? It feels like that may be the best resolution. But when you cease and give it some thought, that’s undoubtedly not the suitable factor to do. If we modify the baseline increased, we’re implicitly saying one thing concerning the worth of manufacturing in 2026. The fee stats? Those projections are good, and we’re not touching them. If we alter the mapping between that offensive manufacturing and WAR, although, we’re beginning to do one thing that is unnecessary.

What is it going to seem like if Ronald Acuña Jr. performs a full season in 2026? We suppose that it’ll seem like a .286/.393/.512 slash line with 31 homers. If he accrues these numbers, what do we predict his WAR will probably be? Our 5.4 estimate might be fairly good, although the best way we get to it appears bizarre. That’s as a result of the precise noticed expertise stage within the majors in 2026 isn’t going to be wherever close to what our purposefully-optimistic enjoying time projections would counsel.

Here’s the true query persons are asking after they have a look at a WAR projection: How beneficial will this participant be, relative to an affordable league common baseline, if he performs a complete season? If we re-centered our preseason WAR estimates across the increased common stage of competitors that we challenge, we’d be answering a distinct query: How beneficial will this participant be if he and in addition each different star in baseball performs a complete season? That second query isn’t the one which’s prime of thoughts. Clearly, then, that technique wouldn’t work.

The query we reply, the one which I feel matches what individuals need, has issues of its personal. Our outcomes are unattainable by nature. They received’t be true within the combination. Fortunately, although, none of these issues really matter all that a lot in the true world. Our projections nonetheless work as a result of they have a look at relative crew energy. The Depth Charts would possibly allocate an excessive amount of WAR to each crew, however it doesn’t allocate an excessive amount of WAR to any star: Each projection is that star’s baseline final result in a wholesome season, precisely what we would like it to be.

I can inform, studying again over this text, that it’s going to be a complicated one. It’s laborious sufficient to speak about how WAR works once we’re already-accrued outcomes; layering in projections and re-centering and allocation clouds the matter even additional. The excellent news is that the takeaways are easy. Our projections do a superb job of determining relative crew energy. They additionally do a superb job of projecting participant expertise stage. They take just a few mathematical shortcuts to get there, however these shortcuts don’t intrude with both of the 2 principal issues the projections are for: answering the questions “How good will this guy be?” and “Will my team make the playoffs?”