If the NFL draft is the lifeblood of a team, it’s not difficult to see why the Cleveland Browns are dying.

In the past four years, the Browns have had seven first-round picks. Only one team had more during that span -- the Minnesota Vikings, who had eight. The St. Louis Rams are right behind the Browns with six.

No team has had less success with those picks than the Browns. The players who should have formed the foundation of a team in Cleveland are instead little more than headaches and question marks. Factor in that three of those picks were in the top 10 and the pain of the failures cuts that much deeper.

The case can be made that the jury remains out on the team's most recent picks, that Johnny Manziel was only this week given a chance as a full-time starter and that Danny Shelton’s work ethic will help him get better.

But the Browns' dubious successes in the draft pale when compared to the other two teams that have had many high picks of late.

Justin Gilbert has not provided the return on investment the Browns hoped for when they selected him No. 8 overall in the 2014 draft. AP Photo/David Richard

Aaron Donald was drafted 13th by St. Louis in 2014, and in his first season, he was named the Defensive Rookie of the Year. This season, he is headed to All-Pro and Pro Bowl selections. Shelton is ranked 97th among interior defensive linemen by ProFootballFocus.com; he was taken 12th in this year's draft.

Teddy Bridgewater was drafted 32nd overall by Minnesota in 2014 and, with the great help of Adrian Peterson, is quarterbacking a 7-2 team. Manziel was taken 22nd in the same draft. He has had well-documented struggles and will be given the next six games to show he can be a long-term solution.

Barkevious Mingo was a No. 6 pick by the Browns in 2013; he’s a backup. Minnesota’s Anthony Barr was taken ninth in 2014; PFF ranks him the NFL’s third-best outside linebacker.

All this illustrates the flaw in the argument of Browns general manager Ray Farmer, who noted that one-third of the league is undrafted free agents. That may be true, but the core -- the foundation of a team -- comes in its drafts.

Farmer guided the last two Cleveland drafts. Mike Lombardi and Joe Banner were responsible for 2013, and Mike Holmgren and Tom Heckert handled 2012. That three different front-office groups were responsible for four drafts says a lot by itself.

Going back to 2012, the Browns' first rounds went this way:

2015: DT Shelton (12) and OL Cam Erving (19)

2014: CB Justin Gilbert (8) and Manziel (22)

2013: LB Mingo (6)

2012: RB Trent Richardson (3) and QB Brandon Weeden (22)

There are two starters among those seven players, and the only reason there are even that many is that Manziel was named the starting quarterback this week. Shelton has started at nose tackle this season. Erving struggled mightily in his first start in Pittsburgh. Gilbert was inactive in Pittsburgh because the Browns preferred to play sixth-round pick Charles Gaines and converted safety Johnson Bademosi. Mingo is a backup with an uncertain future. Richardson and Weeden are no longer on the team.

To think the Browns got so little for those seven picks illustrates why they are floundering.

Then there's this truth: 2011 was the season the Browns traded out of the sixth spot. That trade sent Julio Jones to Atlanta; he has 80 catches, 1,029 yards and six touchdowns already this season. The player the Browns acquired, defensive tackle Phil Taylor, is out of the league due to injuries.

Here are the Rams' last four first rounds:

Count the starters. In fact, don’t count them. There’s no need to. They all start, and Gurley and Donald should go to multiple Pro Bowls. Gurley carries the offense, Donald the defense. Ogletree is out with a broken leg, but he led the team in tackles his first two seasons. The Rams lack a quarterback because previous No. 1 pick Sam Bradford hurt his knee twice, but this group of high picks forms the foundation for the future.

Then there’s this: In 2012, the Rams took cornerback Janoris Jenkins in the second round, and in 2011, they took defensive end Robert Quinn in the first. That’s two more impact starters from high picks.

Here are the Vikings' last four first rounds:

Of the eight picks, six are starters. Barr is a very good young outside linebacker. ProFootballFocus ranks Bridgewater 16th among quarterbacks; in terms of Total QBR, he is 15th. Both are in their second seasons. Smith leads the team in tackles, Barr ranks second. Waynes has struggled, and Patterson is the Vikings’ version of Gilbert -- a high pick who returns kicks. But getting a top returner out of pick No. 29 is much more palatable than getting that same result from pick No. 8.

Lamenting the Browns' drafts these days has become like lamenting the wind and snow in Cleveland's winter -- it’s almost a habit. From 2007 to 2010, the team had three first-round picks and wound up with left tackle Joe Thomas, center Alex Mack and cornerback Joe Haden. That draft success ended there, though.

In fairness, every team has missed on some picks, and it's easy to second-guess. Very few analysts criticized the selections of Shelton or Erving at the time. In fact, those picks were praised as logical and beneficial. In the end, though, players are judged on their production, not on day-after-the-draft analysis.

The Browns' draft opportunities of the past four years provided a chance to build a team. Instead, those opportunities are either already clear failures or on the verge of being declared duds.