A Chrome and Edge extension that puts Baseball Savant contact-quality metrics, batter and pitcher handedness, weekly top-list ranks, and matchup analysis right on your ESPN Fantasy Baseball pages — inline with ESPN's own stats on roster lists, in the player card, and on the matchup boxscore. No more tab-switching to read a player or size up a week.
Beta · Barrel Vision works and is in active use, and is now on the Edge Add-ons store. Chrome Web Store and Firefox listings are still in progress — for those, install it unpacked. The advanced-stats overlay works on any ESPN Fantasy Baseball roster; the matchup analyzer is currently tuned to a standard 10-category weekly head-to-head league (R/HR/RBI/SB/OPS · K/QS/SV/ERA/WHIP, Mon–Sun), with other formats unlocking as they're tested.
Savant's advanced columns land next to ESPN's own stats, with the numbers tinted so the read is instant: 🟥 red = better than your threshold, 🟦 blue = worse, and a stronger tint means further from it. Each player also picks up handedness, weekly top-list ranks, and a day-of matchup rating (▲▲…▼▼).
Pitchers get their own column set (xERA, ERAgap, K% / BB% / K−BB%, and opponent contact quality), with the matchup symbol appearing on a starter's game day.
Open a player card and the same metrics appear as a native-looking Advanced Stats table, plus a collapsible Savant percentile sliders panel (the real value at each percentile, like Savant's own page) and a link to the player's Savant page, for batters and pitchers alike.
Everything is controlled from the toolbar popup, organised into three tabs — one per feature. A master switch turns the whole extension on or off, and every change applies live, with no page reload.
Advanced Stats — per-column Show and Highlight toggles with your own thresholds and direction (higher / lower = better), split into BATTERS and PITCHERS column sets. Refresh advanced data re-pulls from Savant; Reset to defaults restores the stock thresholds.
Top-list ranks — choose where starting-pitcher ranks come from (Pitcher List, Razzball, or RotoBaller); closer and hitter ranks always come from Pitcher List. Toggle each list on its own, see a per-list health line (rows parsed and when they were last cached), Fetch latest ranks on demand, or paste a manual override for a week if a site changes its page.
Matchup analyzer — switch the boxscore projections on or off and see which scoring, timeframe, and categories are in play. These are locked to a standard 10-category weekly league while the analyzer is in beta; Export accuracy log copies the daily projection-vs-actual history out for tuning.
Flip Show debug readout at the bottom of any tab for a one-line data-health HUD — how many Savant hitters/pitchers loaded, rows matched on the current page, handedness records found, and which rank lists are cached. Handy when a value looks off.
On a matchup boxscore or FantasyCast page, Barrel Vision adds a projected weekly total row beneath each team's live category totals — a stable full-week projection with the winning team's cell highlighted in every category. Compare it against the live totals as the week plays out to see who's favored and which categories are still winnable.
Batters: barrel%, hard-hit%, xwOBA, the xwOBA−wOBA gap, avg EV, bat speed, squared-up%.
Pitchers: xERA, the ERA−xERA gap, K%, BB%, K−BB%, opponent xwOBA, opponent barrel%, opponent hard-hit%.
On top of the columns it also:
- Tints ESPN's own OPS, ERA, and WHIP with the same threshold colouring.
- Adds batter and pitcher handedness next to each player ("Milwaukee Brewers • Righty").
- Adds day-of matchup ratings in the opponent column: a ▲▲…▼▼ symbol (🟩 green = good matchup, 🟥 red = tough) from the batter's platoon edge versus the listed starter, or the park-adjusted opponent offense for pitchers.
- Shows weekly top-list ranks beside each player (e.g. "• PL #4"). Starting-pitcher ranks come from your choice of Pitcher List, Razzball, or RotoBaller; closer and hitter ranks come from Pitcher List.
- Projects the full-week matchup on the boxscore / FantasyCast, highlighting the projected category winners (see Matchup analyzer above).
- In the player card, condenses ESPN's columns (OBP+SLG into OPS, W+L into QS, computed as the true season Quality Starts) and adds the Advanced Stats table and percentile sliders.
- Can be turned off entirely from the popup switch or a right-click on the toolbar icon. The overlay disappears live and nothing is fetched while it's off.
Players are matched by name, so there's no setup. Unmatched players just show blank cells.
On Edge, install it straight from the Edge Add-ons store. The Chrome Web Store and Firefox Add-ons listings are still in progress; until they land, load it unpacked:
- Download or clone this repo.
- Open
chrome://extensions(oredge://extensions) and turn on Developer mode. - Click Load unpacked and select the
src/folder. - Open a
fantasy.espn.com/baseball/…roster. The metric columns appear next to ESPN's stats; set your thresholds from the toolbar popup.
Barrel Vision only reads player names from the page and fetches public baseball data (Baseball Savant, the MLB StatsAPI, and the weekly rank sites). It has no host access to ESPN, no analytics, no remote code, and no backend. Nothing from your ESPN session is read or sent anywhere. Full details in PRIVACY.md.
Barrel Vision runs today on ESPN Fantasy Baseball in Chrome and Edge. Planned next:
- More fantasy platforms: Yahoo Fantasy, Sleeper, CBS Sports, and Fantrax.
- More league formats in the matchup analyzer: rotisserie, head-to-head points, daily, and custom category sets (it's locked to a standard 10-category weekly league for now).
- More browsers and store listings: Chrome Web Store and Firefox Add-ons (now live on Edge Add-ons).
MIT © Michael Beardsley. Not affiliated with ESPN, MLB, Pitcher List, Razzball, or RotoBaller. "Baseball Savant" and "Statcast" are properties of MLB Advanced Media.
