MLB NRFI Picks Today, Model Predictions for Friday, April 21
Nick Wosika/Icon Sportswire via Getty Images. Pictured: Anthony DeSclafani
After a slow but very successful Thursday, we have a jam-packed Friday MLB slate.
There's plenty of bets showing as values in my model as every MLB team is 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 nights 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, April 21
Los Angeles Dodgers vs. Chicago Cubs YRFI: We have a 9.5 run total, with Wrigley winds gusting straight out to center field at game time. Mookie Betts' projected return to the top of the Dodgers' lineup is a big boost here, so it might be worth waiting to see if he indeed starts after being used off the bench yesterday.
New York Yankees YRFI: DraftKings offers bets on either team individually to score in the first inning of the game, and that's what we're going with here. New York accounts for roughly two-thirds of the "run equity" in my model, but is being priced somewhat below that at +210 to score in the first. I would pivot to the -110 both teams line at BetMGM if this fell below +190 or so. (Also consider betting half of your usual unit here.)
Detroit Tigers vs. Baltimore Orioles YRFI: Most of the value is on the Baltimore side here, but Detroit's lineup has perked up a bit in recent games and Baltimore starter Tyler Wells is nothing to be afraid of. You could go Baltimore only here, but the math works out slightly better on the traditional YRFI
Minnesota Twins vs. Washington Nationals YRFI: Only an eight-run total here, but both pitchers have been slightly worse their first time through the order, with a fairly comfortable sample size. Projecting a bit better than 50% so worth taking at plus-money odds.
Los Angeles Angels vs. Kansas City Royals YRFI: My gravestone will read "bet Angels YRFIs." Los Angeles makes up the vast majority of the equity here, but is priced like it too, making the full game line the better pick mathematically. I wouldn't blame anyone for taking the Angels only at better odds.
St. Louis Cardinals vs. Seattle Mariners NRFI: Eight run game total here, with two pitchers who fare better early in games. Not a massive edge but any star hitters for either side getting the night off can only help us here. Additionally, the Cardinals' lineup is dominant against left-handed pitching, but is only slightly above average against righties like it faces tonight.
New York Mets vs. San Francisco Giants NRFI: The top of the Mets' lineup is a bit scary, but the Giants have been dreadful against lefties in 2023. I expected the NRFI line to be a lot juicier on this game.
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