In the advanced era of baseball numbers-crunching, Twins Chief Baseball Officer Derek Falvey talked with Star Tribune baseball writer La Velle E. Neal III about meaningful statistics.

Offense: What is WOBA?

We have graduated from batting average to the slash line (batting average/on-base percentage/slugging percentage) and even to OPS (on-base plus slugging percentage). But Falvey likes weighted on-base average (wOBA), considered to be the best way to measure total offensive value.

"Take a look at the top 30 teams and rank all of them by runs scored," Falvey said. "Any other stat next to it — batting average, on-base percentage, slugging, etc. What's most highly correlated to runs scored? Weighted on-base."

The Twins scored 722 runs last season, 16th in baseball. Their team wOBA was .317, good for 14th.

Brian Dozier led the Twins with a .370 wOBA. Leaguewide, he was 26th. Guess who was second? In 99 games, Robbie Grossman had a .363 wOBA. And you wondered why he was still on the team.

If you're baffled while trying to put together a batting order, look at wOBA, bunch the best at the top of the order and go for the ambush.

Defense: Metric debate

There's range factor, ultimate zone range, defensive runs saved, John Dewan's plus-minus system and others. Those stats help tell the story of defensive efficiency but miss the mark in various ways. Why give someone credit for a great catch when he runs a poor route? What about the effect of shifting?

It has led some to synthesize their own formulas.

"Every team has its own internally developed defensive metrics," Falvey said.

The folks at Statcast introduced catch probability, which categorizes catches from low to high probability. It notes where the fielder was positioned and how far he ran, where the ball was hit and how long it was in the air.

"That's probably going to end up being my favorite," Falvey said. "If you are shifted or you're playing somewhere in the outfield where you have to make up meaningful ground to make a play — that's different than a ball hit right at the guy. It is important to know where a guy is positioned and how much that plays into the defense."

Starting pitching: It's WAR

There are many ways to evaluate pitchers beyond win-loss record and ERA. There's batting average on balls in play, walk percentages, strikeout percentages and fielding independent pitching (FIP) that focuses on outcomes over which a pitcher has control, such as strikeouts, walks and home runs.

Falvey leans toward wins above replacement (WAR), perhaps the best way to look at a player's overall contribution.

The Mets' Noah Syndergaard led baseball with a 6.5 WAR last season, according to

fangraphs.com. The Twins' leader was Ervin Santana at 3.2.

Falvey thinks WAR can help in comparing pitchers who have produced differently.

"We have a hard time as an industry sometimes separating out the guy who throws 200 innings but has a league-average performance vs. the guy who throws 120 innings but at a much higher performance," Falvey said. "What's more valuable? If there's a way to blend quality and quantity, WAR gives you that."

Relief pitching: Specializing

A specialist reliever like Craig Breslow can be valuable in a vastly different way than someone like Cleveland's Andrew Miller, who can pitch two or three innings if needed.

"You are going to look at something different for those guys than for the overall volume metric," Falvey said. "How they perform against lefties, guys who are so unique and specialized that you will want to look at more unique stats for them."

General Manager Thad Levine agrees. He looks more at strikeout rates and walk rates for relievers "because preventing baserunners becomes more important later in the game."

Michael Tonkin struck out 10.0 batters per nine innings last season, and the Twins could use more relievers with that type of production. But Tonkin walked 3.0 batters per nine innings, and opponents had a .344 average against him on balls put in play (BABIP) — both of those could be better. His WAR of 0.1 reflects the unevenness of his season.