The Cavaliers are suddenly a defensive juggernaut, and it's the biggest reason they're stunning the Warriors

The Cleveland Cavaliers were a bad defensive team at the beginning of the season. Through the first 38 games of the year, during which they went 19-19, they had the sixth-worst defensive rating in the league at 106.0 points per 100 possessions.

After LeBron James returned from a two-week break and they traded for J.R. Smith, Iman Shumpert, and Timofey Mozgov, they improved to an average defensive team. Over the last 44 games of the season, during which they went 34-10, they ranked 15th in the league in defensive rating at 102.5 points per 100 possessions.

In the playoffs, they have, incredibly, completed the transition from one of the worst defensive teams in the league to one of the best defensive teams in the league. They're allowing 98.7 points per 100 possessions in the postseason, which would have ranked 2nd in the NBA this year.

With Kevin Love and Kyrie Irving injured, Cleveland's defense is the biggest reason they're tied 1-1 in the NBA Finals against the heavily favored Golden State Warriors. 

Over the last two games they've made the 2nd-best offensive team in the league look ordinary. The Warriors had a 109.8 offensive rating in the regular season. In the Finals, they're at 99.7 - which, for perspective, is the offensive rating the 27th-ranked Orlando Magic had in the regular season.

In Game 2, Irving's replacement Matthew Dellavedova harassed Stephen Curry into one of the worst shooting nights of his career:

The injuries to Irving and Love have been devastating offensively. The Cavs' offensive rating is a dismal 92.0 in the Finals. But defensively, they've been better without two of their three superstars. Tristan Thompson is an improvement over Love at the defensive end, and Dellavedova (while not exactly known as a stopper) is at least as good as Irving when guarding Curry.

Beyond those two, Timofey Mozgov has been fantastic. When the Russian center is on the floor the Cavs defensive rating improves to a ridiculous 95.8 points per 100 possessions. 

While LeBron James has been magnificent offensively, it's just impossible to be very efficient as a team with the way they're relying on isolations. Their defense is saving them right now.

What was once an offensive juggernaut that couldn't buy a stop is now a defensive juggernaut that only scores enough to win because LeBron is so brilliant.