OOPSY Peak Projections Are Now Live on FanGraphs!

OOPSY peak projections for all minor and major league players are now available for FanGraphs Members.

I’ve been publishing current season OOPSY projections since 2025. They broadly fit in with the other FanGraphs systems in terms of methodology (and accuracy), though like all projection systems, they have their own methodological quirks. OOPSY makes use of its own aging curves, major league equivalencies, park factors, league scoring environment factors, regression, and recency weights to project players. For those interested in learning more, the OOPSY introduction, 2025 review, and recent Top 100 Prospects list provide a more detailed overview of my methodology.

Since 2022, OOPSY peak projections have been featured on Scout the Statline and, since 2024, they have also been featured on RotoGraphs, where I’ve used them to generate fantasy-oriented top prospect lists. Last month, after incorporating defense into the projections using our prospect team’s work on The Board, I published OOPSY’s first top prospect list with a real-life focus, ranking prospects by peak projected WAR.

All projection systems utilize aging curves to produce future or peak projections, but only some actually publish them. At FanGraphs, the closest thing to peak projections are the ZiPS three-year forecasts; I’ve used ZiPS peak forecasts to produce prospect rankings. Across the baseball community, peak projections have grown in popularity in recent years: Clay Davenport has been doing peak projections for a while, Dylan White produces his own variation at Baseball America, and Voros McCracken started producing publicly available peak forecasts this offseason.

OOPSY peak projections assume a player’s peak occurs around 28 years old, with most development occurring before 25. While some projection systems use player comparables or physical characteristics to devise unique aging curves for each player, OOPSY opts for an agnostic approach to aging, assigning the same, Marcel-inspired, generic aging curve to each player. Each component statistic gets its own aging curve, however, with some components, like strikeout rate for pitchers, peaking early, and others, like walk rate for pitchers and hitters, peaking later.

So what exactly are OOPSY peak projections? It may be helpful to start by clarifying what they are not: 90th-percentile projections. On the contrary, they are identical to the current season OOPSY projections — projecting a player’s mean performance, or true-talent level, in a given season — except for a few important differences. First, OOPSY peak projections use aging curves to extrapolate current projections into the future until a player’s peak, age-28 season. Second, OOPSY peak projections are context-neutral, assuming a neutral big league park in the 2025 major league run environment. Third, OOPSY peak projections are playing time neutral and unaware of injuries, projecting all players for the same amount of playing time: 600 plate appearances for hitters, 198 innings for starting pitchers, and 70 innings for relievers. For starting pitchers, the projections are adjusted to assume a six innings per start workload, controlling for the fact that starting pitching prospects often have very different usage in the minor leagues.

OOPSY peak projections take inspiration from Steamer600 and context-neutral Steamer projections, and it is no coincidence that the OOPSY peak projections can be found next to Steamer600 on FanGraphs — hooray, neighbors! OOPSY peak projections do deviate from Steamer600 when it comes to catcher playing time, however: Instead of Steamer600’s 450 plate appearances, they give catchers 600 plate appearances, with most assumed to occur at catcher, and the rest assumed to occur at designated hitter.

Finally, how do OOPSY peak projections handle veterans who are older than 28? For these players, context-neutral current OOPSY projections are displayed rather than peak projections. The idea is that this approach provides a rough, straightforward approximation of how veterans and prospects tend to be valued, based on current value and future value, respectively. This approach makes it easier to compare the stars of today with the stars of tomorrow. For instance, Konnor Griffin is OOPSY’s top hitting prospect, with a peak projected WAR of five, which would make him approximately the 14th-best hitter in baseball at peak, or as good as Ronald Acuña Jr. is now according to OOPSY.

OOPSY peak projections rank hitters and pitchers by WAR, the same way prospects were ranked in this year’s OOPSY Top 100. In general, WAR is computed following the FanGraphs approach, though for pitchers both standard WAR and RA9 WAR are displayed, and RA9 WAR was used in my Top 100 given that pitcher BABIP projections are less subject to random variation than actual BABIP (Members can export the CSV to see both versions of WAR).

Here, I’ll remind readers that OOPSY captures all minor and major league performance, except for the Dominican Summer League and the Arizona Fall League. Further, it does not capture high school or college performance, meaning you should use it with extra care for players from the 2025 draft class; those players are automatically excluded if they have fewer than 50 career professional plate appearances or total batters faced. Finally, while OOPSY ignores scouting, aside from incorporating the aforementioned Fielding grades from The Board, I would advise against using it as a substitute for scouting. It is, on the contrary, intended to serve as a complement to scouting.

OOPSY peak projections will be refreshed for FanGraphs Members a couple of times a year. My hope is to refresh them once midseason, once right after the season is over, and once in the months leading up to the season, each time with a companion Top 100 prospects update, leveraging the latest minor and major league stats, plus updated defensive data from The Board. Additionally, for those who just can’t get enough OOPSY, daily updates to the peak projections can be found at Scout the Statline during the season.