Thursday was another solid day for the NRFI model, going 3-1 for a nice profit. Friday gives us another chance to add on with a full slate of games and every MLB team in action.
The Model
The process is relatively simple. First, I start by assuming that the full-game (implied) run totals for either team are roughly efficient. As mentioned above, that tends to be the case more often than not. This saves me the trouble of trying to predict the total runs scored in the game — and allows me to focus strictly on the "when" rather than "how many."
Next, I built a database of pitchers' performance the first time through the order, relative to their overall stats. Since the latter is presumably baked into the full-game total, I wanted to figure out if those runs are more likely to come early or late. Most — but not all — MLB starters do somewhat better early in games, but with some variance in just how much. The model uses xFIP (expected Fielding Independent Pitching) as the ERA predictor of choice.
That's only half of the equation, though, with the offenses making up the other half. To do this, I looked at what percentage of a team's total runs is produced by the top-three batters in the lineup. While a first-inning run scored, by definition, needs at least four hitters to come to the plate, one of the first three has to actually score it. The metric of choice here is wRC+, based on the projected lineup for the day from each team.
This is a bit of a tradeoff, as lineups (and run totals) can shift throughout the day, especially if significant contributors miss time. However, in my experience, the inefficiency of the morning lines more than makes up for the leakage in the model. With that said, exercise caution if, say, Mike Trout is listed as questionable for the night's game.
The Picks
With all of the picks below, I'll include the pick, the best line and the threshold I'd bet it to. These will go up in the morning, so if any major news breaks between publishing and when you read it, be sure to consider that.
Infrequently, rather than betting on the traditional YRFI/NRFI, the pick will be on one team or the other specifically to score a run, which as of this writing is only a betting option at DraftKings. Since the model handles each team individually, sometimes one team is projecting for a greater proportion of the "run equity" in the first inning than the betting lines are accounting for.
NRFI Odds, Picks for Friday, August 4
Kansas City Royals vs. Philadelphia Phillies NRFI: I prefer to take this line on BetMGM thanks to their Friday NRFI promo, which makes sacrificing the few cents of value on the line more than worth it. The best line is at BetRivers, though, and is a massive value at +107.
New York Mets vs. Baltimore Orioles YRFI: We're getting a bit of an off line at Kambi-associated sportsbooks (BetRivers, Play Gun Lake, etc), which makes this one a solid value. Both starting pitchers have higher xFIP numbers their first time through the order than overall, and the solid nine-run implied total helps the projection as well.
Miami Marlins vs. Texas Rangers NRFI: Marlins vs. Rangers features an 8.5-run total plus two pitchers with excellent first time through the order splits. While Miami is fairly top-heavy offensively, Texas ranks below average in that regard, which mostly cancels it out.
Los Angeles Dodgers vs. San Diego Padres YRFI: The Dodgers and Padres rank first and seventh respectively in production share by their top-three hitters, making this a YRFI I'm likely to take all series.
