NFL teams put a lot of preparation into drafting players, but ultimately, the selection process can be a crapshoot.

Case in point: former San Diego Chargers quarterback Ryan Leaf. He was drafted No. 2 overall in 1998, went 4-14 in three seasons with the team, fell out of the league in 2001, and wound up in prison on burglary and drug charges.

To highlight the importance of draft value - or performance relative to a player's draft position - over draft position alone, the folks at Casino.org analysed every pick since 1960 to see how well players and teams have done in this regard.

When it comes to finding quality draft picks, they found no one does it better in the NFL on average than the Dallas Cowboys, Minnesota Vikings, and Miami Dolphins.

The Washington Redskins find themselves at the bottom of the list with the league's worst draft quality, followed by the St. Louis Rams and Tennessee Titans.

The study also looked to identify teams that have gotten the most value out of picks at each position. The Dolphins are particularly good at finding value at the quarterback and secondary positions, while the Indianapolis (formerly Baltimore) Colts have fared the best at running back.

Here are a few other findings from the study: