It's been a strong week so far with back-to-back profitable days betting on first-inning runs. Wednesday brings a full slate of games, with some afternoon bets to sweat as well.
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 selection, 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 a betting option only 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 Wednesday, May 24
Pittsburgh Pirates vs. Texas Rangers YRFI: The nine-run total is almost enough to justify a low-juice YRFI bet in and of itself since we're expecting as many runs as innings in this game. Both offenses get a greater-than-average share of their offense from the tops of their lineups, as well.
Minnesota Twins vs. San Francisco Giants NRFI: I'm willing to pay the heavier juice for this one, thanks to a low game total and two pitchers with above-average first-time-through-the-order splits. The day game following a night game also raises the odds that one of either team's top hitters gets the afternoon off – particularly Byron Buxton, who has been "load managed" a bit this year.
Tampa Bay Rays vs. Toronto Blue Jayes YRFI: The lefty-on-lefty pitching matchup is big here, with both teams ranking above average against left-handed pitching. Tampa Bay has a team wRC+ of 159 against southpaws – by far the best number in the league. They provide the bulk of the value here. Tampa's starter, Shane McClanahan, has strong overall numbers, but he has "reverse splits" early in games that give the Blue Jays reasonable scoring equity too.
Atlanta Braves vs. Los Angeles Dodgers YRFI: The Dodgers and Braves rank first and seventh, respectively, in the proportion of their offense provided by their top three hitters. With a 9.5-run implied total, this is projecting extremely well.
