Better Know An Umpire: Laz Diaz
Welcome to Better Know An Umpire, an effort to educate ourselves on the human elements who have ultimate decision-making power over some 2,500 Major League Baseball games a year. (All cumulative statistics are through the 2011 season, unless otherwise stated.)
Name: Laz Diaz
Uniform number: 63
Age: 49
Height/weight: 5-foot-11, 210 pounds
First year as MLB umpire: 1995
Total MLB games worked through 2011: 1,743 (home plate: 442)
Previous experience: International League
Career ejections: 23
No-hitters called: None
Over/under record ( 1999-2011): 187-198
Hated in: DC, Cleveland
Notable alleged blown calls: Nationals-Reds, April 15, 2012; White Sox-Indians, August 16, 2011.
Claim to fame: Diaz was attacked by a drunken fan during a game at US Cellular Field on April 15, 2003. Diaz, who was not hurt, later said, "We spoke about it in the locker room, this is where Tom Gamboa got attacked. We thought nothing was going to happen, but it was a full moon out there." Eric Dybas later pled guilty and got six months in jail.
Scouting report from Major League Umpires' Performance, 2007-2010, by Andy Goldblatt:
He has just 23 ejections in over 1,600 games, a rate less than two-thirds the average. He tallied a mere six ejections from 2007 through 2010. ... Pitchers are happy to have Diaz in charge. His overall 2.45 K/BB ratio is tenth highest. ... There is no question that Diaz has one of the largest strike zones among major league umpires.
Scouting report from SB Nation's Chris Mottram:
Also, Laz Diaz is just fucking awful, if it wasn't already clear.
Average K/9 ( 2011): 13.8
Average BB/9 ( 2011): 5.7
Sample PITCHf/x strike zone: July 1, 2011. Dustin Pedroia nearly got ejected for arguing a low called strike, but Diaz was all over the zone for both clubs all evening.
True fact: Served in the Marine Corps Reserve for 12 years: "I attribute a lot to the Marine Corps, just the way that they give you the attitude to be your best, to work hard. ... The Marine Corps - boot camp especially - helped me through my umpiring. Discipline, being able to adjust to the situation, being able to endure the comments from the fans and from the players. I heard words from A to Z in boot camp. You have to take it, not being able to respond or lash out. It gives you a tough skin."
Strike 3 call:
To check out other installments of Better Know An Umpire, click here.
The Minnesota Twins Should've Traded Pablo Lopez Last Year
Why the NBA’s Tanking Problem Isn’t What You Think
Three Quarterbacks With the Most to Prove at the NFL Combine
Are the Pittsburgh Pirates Finally Ready to Contend in 2026?
Two Massive Questions That Will Define the NBA’s Second Half
- Best 2026 American League East Season-Long Future Betting Predictions
- Best College Basketball Bets for Monday: Duke vs Syracuse, Houston vs Iowa State
- NBA All-Star Game Betting Preview: Best Picks for World vs. USA and MVP Odds
- NBA All-Star Saturday Picks: Best Bets for the 3-Point Contest and Shooting Stars
- NBA Three-Point Contest 2026 Best Picks and Prediction Markets for All-Star Saturday
- NBA Picks Tonight: Three Best Bets Before the All-Star Break
- Best NBA Betting Picks for Wednesday Feb. 11th Slate

