Tobias J. Moskowitz and L. Jon Wertheim

Whistle Swallowing

  • All about officials and omission bias with loss aversion

  • Uses Mike Carey and David Tyree catch as fundamental example.

Acts of Omission

  • The absence of an act - as far less harmful than acts of commission - actually committing the act, even if the outcomes are the same or worse

  • Food example - declining healthy food is a poor choice (omission), but eating junk food is worse (commission)

Omission or Comission

  • Jeff Bezos quote - “people overfocus on errors of commission, failure’s not that expensive, the big cost you incur is harder to notice, errors of omission.”

  • Officials or refs, when the game steps up, you step down

Subjective calls

  • Swallow the whistle with judgement calls versus subjective calls when the game is about to end

  • Subjective in football - holding, illegal blocks, illegal contact, and unnecessary roughness don’t happen as often when game is on the line or at its end

  • Objective calls - delay of game, illegal formation, motion, or shift are called at the same rate

Go for it

  • Kevin Kelley always going for it on 4th down and never punting

  • He plays the odds and he also has job security and freedom to do so

  • All about risk aversion

Losing hurts

  • Sparky Anderson - losing hurts twice as bad as winning feels good.

  • Would you rather want a $5 discount or avoid a $5 surcharge?

Why take risks

  • You’re more likely to risk something when you expect to lose

  • Job security is huge. Are you allowed to fail or be unconventional?

  • Belichick was not as aggressive until he won a Super Bowl. It built equity for him to take risks, fail, and not lose his job

LaRussa example

  • Players must buy in too.

  • Tony LaRussa tried using pitchers for 3 innings apiece, but players didn’t like it. They wanted wins (throw for 5 innings), because it drives their contracts

Westhead example

  • Paul Westhead’s playing style at Lakers, didn’t work

  • It worked at Loyola Marymount, but failed spectacularly with Denver Nuggets

  • Players buy in matters.

Tiger Woods is human

  • More about loss aversion, it’s a principle we dislike losing a dollar more than we enjoy earning a dollar

  • PGA tour, measured putts from identical distance for birdies and pars, putts for par were far more successful

  • Players were so concerned with a loss, you’re more aggressive in avoiding bogey than scoring birdie

Birdie putts

  • Tendency to leave putts short for birdie, being too conservative.

  • Woods even says the psychological difference between making a birdie and dropping a shot is huge, more important to make a par putt. He’s human

Gain and loss

  • In the face of gain, we’re conservative

  • In the face of loss, we’re aggressive.

  • It’s hard to block out how you got in a predicament. Remain even keel

Endowment effect

  • Feel the loss of something you own much more deeply than the loss of something you don’t own

  • When you own, you’re invested emotionally in a thing versus not tied to it

Offense wins Championships

  • Defense is no more important than offense, both are equally important

  • Defense requires effort, it’s less glorified, harder to measure, and dark (hidden)

Value of a blocked shot

  • The value of blocked shots is in the details.

  • Blocked shot back to opponent was assigned a value

  • Blocked shot out of bounds was slightly more valuable

  • Blocked ball to a teammate was worth the most

Value of the act

  • It’s the value of the act, not the act itself that matters

  • Counting is easy, measuring value is hard

  • Tim Duncan’s 149 blocks were more valuable than Dwight Howard’s 232 blocks

Rounding first

  • People have a bias to round numbers

  • It’s why more batters hit .300 than .299.

  • A batter is close to .300 at end of season? He won’t play.

Incentive bias

  • A rounder number (100 RBI, .300) usually leads to better salary

  • Bobby Abreu finished with exactly 20 or 30 home runs five times, seven times exactly 100 or 100 RBI, and no seasons with 95 to 99 RBI

  • Same true in NFL with 1,000 rushers

Where to find value?

  • You can find value in looking at players just below these round number benchmarks

  • Just below .300 or below 1,000 rushers

Rooney Rule

  • The drop-off of African American coaches winning is actually a good thing

  • Why? It validates the Rooney rule

  • Black coaches are held to same standard as white counterparts. They’re equal

Comforts of Home

  • There is a home-field advantage in all sports

  • It’s a bit more strong in some sports, but it’s the same regardless of where sport is played

  • There is significant incentive to win at home - concessions, people leave happy, spend more money

Why does home field advantage exist?

  • Because of crowd support? No. Look at kicks in football, free throws, shootouts - when you control for a situation where crowd could impact game, it really doesn’t

  • Because of travel? No, evidence isn’t strong that travel plays a major role.

  • Because of scheduling? Yes.


  • NBA teams play lots of back-to-back games, and this does favor the home team

  • It’s less of an issue in certain sports like MLB

  • More extreme in college football. Teams pad schedule with hosting weak opponents

Home field advantages

  • Scheduling bias explains some of home field advantage, but not in baseball or NFL or soccer at all

  • Because of unique home characteristics? Not really, some impact, but not huge difference. Hard to really have an edge with unique home fields today


  • Officials or referee bias is most significant factor

  • Study used QuesTec data to determine officials or umpires side with the home team in pressure situations on borderline calls

  • More ambiguous the call? More likely to go in home team’s favor.

  • Humans conform because they want to fit in and because they believe the group is better informed than they are

  • Officials aren’t really aware of the bias, it’s just a natural human response

  • Why does home field advantage differ across sports?

  • Because refs or officials are more important or have more influence on the game. Soccer more than baseball. A penalty kick is huge, where umpire calls are fairly black and white.

  • Why is it the same for a sport no matter where its played?

  • Because the role of the referee is the same no matter if soccer is played in America or Europe or Spain.

  • Why hasn’t it changed much over time?

  • Because the officials role hasn’t changed with the rules.

No I in team

  • But there is an m and an e

  • There is a bigger influence of superstars in certain sports like basketball

  • Disagree with soccer, think it’s much less

  • Makes sense in basketball. Only 5 players play at a time

Michael Jordan

  • Where in baseball, a player might only get 3 at-bats a game

  • In soccer, only a few touches by your best attacker.

  • Michael Jordan - There is an I in win. So which way do you want it?

NFL Trades

  • Off the chart Mike McCoy came to own the NFL draft using a value chart that was largely designed off assumptions.

  • Tried to answer - what is the value of a draft pick in a certain round?

  • Value of the first pick in draft was 3000, and first pick in second round 580, and final pick was 0.4

Charts give value

  • The chart just gave the Cowboys a framework

  • It more or less stated value in multiple picks versus one high pick

  • Opposite is when the Saints traded eight draft picks for Ricky Williams. Overpaid by a ton

Why did it become obsolete?

  • Eventually when all teams started using the chart, it became obsolete

  • Thaler and Massey found inefficiencies

  • Teams would overpay to pick today versus playing the long game. Not comfortable with uncertainty

Evaluating Talent

  • It takes talent to evaluate talent.

  • Draft pick value is different for different sports. Seven rounds in NFL, just two in NBA, and 50 in MLB

  • Find value by looking at the details. Ask why

  • Brady didn’t play at Michigan more because of political reasons than his ability

Rule Changes

  • Coin toss trumps all: If you won the coin toss in overtime for NFL, you win 61 percent of time

  • This prompted changes in the NFL overtime rule. It wasn’t really fair

Mitchell Report

  • What isn’t in the Mitchell Report Dominican players were more likely to take steroids because of cultural and situational needs

  • All incentive bias

  • The upside was far greater for Dominican players than American players. A lot of Dominicans were much younger, where American players were older and trying to get one last big contract

Does icing the kicker or shooter work?

  • No. It’s a lukewarm strategy.

  • Study looked at NFL kicks and NBA free throws. Found no difference in performance

Myth of the hot hand

  • Momentum in sports doesn’t exist. We just believe it does because we like patterns

  • We don’t like mystery.

  • Randomness and luck resist explanation


  • Try flipping a coin 100 times. There will be streaks of heads or tails

  • Those streaks don’t increase the odds the next flip will land on heads.

  • We do a really poor job at understanding randomness. You aren’t due for anything. Your chances do not change because of a streak.

Sample sizes and Randomness

  • The true quality of teams can be measured in large sample sizes

  • Small samples are dominated by randomness


  • You can make numbers say whatever you want. It’s selective. And more than one thing can be true

  • Be objective. Neutral. Look at as much data as possible to get a more accurate picture

  • Not just short-term numbers

Cubs cursed?

  • No, they’re not cursed or super unlucky.

  • It was deeply ingrained in the team that wins and losses didn’t matter

  • Wrigley wanted fans to enjoy the ballgame, win or lose. Lovable losers

  • Cubs could lose and attendance could go up. This wasn’t the case for almost all other teams.

  • Beer prices remained flat. Cubs fans went to game for experience, not for wins.

  • Curses aren’t to blame or Steve Bartman.

Purpose of the book

  • Ignore data and diverse views as your own peril

  • Seek controversial or opposite opinions and challenge convention to improve your decision making