Worth and value are two different things that don't always match up in the NFL.

For the past three seasons, the Texans have gotten an incredible bargain on superstar defensive end J.J. Watt. They rectified that Monday night, agreeing to a six-year extension that means instead of $1.9 million this season, Watt will get more than $30 million when he signs his contract on Tuesday.

His total guaranteed money -- which, according to reports, fully kicks in if he's on the roster in 2016 -- is $51.8 million, the highest guarantee for any defensive player.

He's worth it because of his value to the Texans' defense.

Watt has never missed a game in the NFL, but he doesn't play every snap. The statistical difference with Watt on the field versus with Watt off it is dramatic.

According to ESPN Stats & Information, with Watt on the field teams average 4.1 yards per rush and have a Total QBR of 47.2. Without him, both of those numbers rise, to 4.4 yards per rush and a Total QBR of 57.2.

As for sacks? With Watt on the field, the Texans' sack percentage jumps from 4.0 without him to 7.1 with him.

Since 2011, when the Texans drafted him 11th overall, Watt has disrupted more drop-backs than any other player. The plays that count among disrupted drop-backs are sacks, passes defensed, batted balls and interceptions. Watt has 62.5 during the past three seasons, topping Jared Allen (56.5), Richard Sherman (49) and Joe Haden (48).

It's a function of Watt's belief that he's never truly beaten. When another player might consider a play finished, Watt often figures out how to make the most of it.