The Approach Angle

TAA 11 - What to Make of ERA Estimators

The Approach Angle Nate Schwartz (@_nateschwartz [https://x.com/_nateschwartz]) and Kyle Bland (@blandalytics [https://x.com/blandalytics]) about ERA estimators and how to apply them. The discussion starts by talking about why ERA needs to be estimated. There are so many factors that go into run prevention that make it hard to value a pitcher just on ERA. They first dive into FIP, breaking down why it makes sense to remove balls in play from the equation entirely. This starts the focus on strikeouts and walks as the main identifer across the board. The chat moves to xFIP, which adjusts for league-average home run rate. Next, the two talk about SIERA, and how it's complex compared to the others and is the most predictive. After covering the main ERA estimators, they shift to how xERA is powered by Statcast data, but that doesn't make it more predictive. Finally, they wrap up by mentioning PLA, Pitcher List's scaled stat for pitch level value (PLV) and the players that stand out across these estimators. Articles discussed: The Relative Value of FIP, xFIP, SIERA, and xERA Pt. II [https://pitcherlist.com/the-relative-value-of-fip-xfip-siera-and-xera-pt-ii/], Dan Richards; pFIP: Pitch Height, Launch Angle, and the FIP Framework [https://fantasy.fangraphs.com/pfip-pitch-height-launch-angle-and-the-fip-framework/], Alex Chamberlain; Predictive Classified Run Average [https://fantasy.fangraphs.com/era-estimators-pt-ii-present/], Connor Kurcon; What is PLV? [https://pitcherlist.com/what-is-plv-an-introduction-to-pitch-level-value-and-its-applications/], Nick Pollack Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com [https://pcm.adswizz.com] for information about our collection and use of personal data for advertising.

TAA 10 - Do We Have Any Discipline?

The Approach Angle Nate Schwartz (@_nateschwartz [https://x.com/_nateschwartz]) and Kyle Bland (@blandalytics [https://x.com/blandalytics]) break down swing rates and contact rates for hitters. The discussion starts with how ABS has changed parts of how we value plate discipline, and how good discipline can play into challenges. They dive into swing rates: they start with how overall swing rate doesn't necessarily mean anything on its own, but can show outlier trends. Breaking it out into zone swing and out-of-zone swing (chase rate), they mention chase rate's importance because no good outcome can come from a chase swing. They move into contact rates, focusing on the importance of zone contact. Overall, they note how important it is that swings in the zone still struggle to create run value, emphasizing decision-making relative to contact ability. Finally, they close by talking about Pitcher List's decision value and contact ability, and what goes into those stats. Articles discussed: Quantifying the Corey Seager Approach [https://www.baseballprospectus.com/news/article/86572/the-crooked-inning-corey-seager-rangers/], Robert Orr; The Westburg Paradox [https://pitcherlist.com/the-westburg-paradox/], Tanner McGrath; Chasers Gonna Chase, but Where? [https://blogs.fangraphs.com/chasers-gonna-chase-but-where/], Davy Andrews; Heart of the Zone Value Tweet [https://x.com/blandalytics/status/1752186748569059598], Kyle Bland; STIO Tweet [https://x.com/blandalytics/status/1823820111570198797], Kyle Bland Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com [https://pcm.adswizz.com] for information about our collection and use of personal data for advertising.

TAA 9 - Creating Our Own Game Score

The Approach Angle Nate Schwartz (@_nateschwartz [https://x.com/_nateschwartz]) and Kyle Bland (@blandalytics [https://x.com/blandalytics]) talk about different versions of game score. They start by talking about the theory behind the original game score, which was created by Bill James. That leads to the second version of game score, developed by Tom Tango, where the two talk about the philosophical differences in what a game score is meant to capture. Then they talk about how Kyle went about creating his version of the game score and what he wanted to get out of it. They extensively discuss the crowd-sourced rankings and how it applies to the letter grades with the pitch cards. Finally, they conclude with ideas for stats to include in a "start watchability" index. Articles discussed: Game Scores [https://baseballanalysts.com/archives/2005/01/abstracts_from_23.php], Bill James; Game Score Version 2.0 [https://blogs.fangraphs.com/instagraphs/game-score-v2-0/], Tom Tango; Explaining Pitcher List’s Player Card Grades [https://pitcherlist.com/explaining-pitcher-lists-player-card-grades/], Kyle Bland   Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com [https://pcm.adswizz.com] for information about our collection and use of personal data for advertising.

TAA 8 - What Are Park Factors Worth?

The Approach Angle Nate Schwartz (@_nateschwartz [https://x.com/_nateschwartz]) and Kyle Bland (@blandalytics [https://x.com/blandalytics]) are joined by Sara Sanchez to talk about park factors. The discussion starts with the group talking about what goes into park factors and what they actually mean. They discuss how specific factors, such as HR or strikeout factors, can be more important than the overall factor at times. They also talk about how the weather can get baked into some park factors and ignored in others (such as the wind in Wrigley). Next, they get into how players prepare and adapt to different parks, both offensively and defensively. Finally, Kyle explains how park factors get integrated into daily & weekly projections, and Sara talks about how controlled environments in domes is good for pitchers. Articles discussed: An Updated System of Park Factors (and Volatility) [https://www.baseballprospectus.com/news/article/64534/an-updated-system-of-park-factors-and-volatility/], Jonathan Judge; The Park Factors are in the Pudding [https://blogs.fangraphs.com/the-park-factors-are-in-the-pudding/], Kiri Oler; The Impact of Changing Park Factors Around Baseball (Pt. 1) [https://ftnfantasy.com/fantasy-baseball-2025-the-impact-of-changing-park-factors-around-baseball-pt-1] Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com [https://pcm.adswizz.com] for information about our collection and use of personal data for advertising.

TAA 7 - What Does wRC+ Actually Measure

The Approach Angle Nate Schwartz (@_nateschwartz [https://x.com/_nateschwartz]) and Kyle Bland (@blandalytics [https://x.com/blandalytics]) talk about what goes into wRC+ and why it's a strong, all-encompassing hitter stat. They start by discussing wOBA—the basis for wRC+. It's an important hitting stat that values outcomes in a slightly stronger way than OPS. Surprisingly, the under-the-surface nuances are more understandable for wOBA than OPS. They transition into talking about how wRC+ includes factors such as league environment and park factors, making it a useful contextual tool for any hitter. Additionally, they discuss how the single number can be useful for analyzing player quality but can miss some fantasy-specific stats. Finally, they discuss any gaps in wRC+ and how stable it is. Process+ is also mentioned as an effective tool to predict wRC+ both in-season and across seasons.. Articles discussed: Weighted On Base Average or wOBA [https://www.insidethebook.com/woba.shtml], Tom Tango; Guts! [https://www.fangraphs.com/tools/guts?type=cn], Fangraphs; DRC+: Updates and Improvements [https://www.baseballprospectus.com/news/article/46944/drc-updates-and-improvements/], Jonathan Judge; What is Process+? Pitcher List’s New All-Encompassing Hitting Stat [https://pitcherlist.com/what-is-process-pitcher-lists-new-all-encompassing-hitting-stat/], Nate Schwartz (shameless self-plug) Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com [https://pcm.adswizz.com] for information about our collection and use of personal data for advertising.