An oft-repeated statistic as the Vikings have struggled with their offensive line this season is this: in the past decade worth of drafts — 10 of them between 2007 and 2016 — the Vikings have invested a grand total of two picks in the top three rounds to offensive linemen.

Both picks — second-round tackle Phil Loadholt in 2009 and first-round tackle Matt Kalil in 2012 — were mainstays when healthy (to varying degrees of effectiveness), but neither is contributing right now.

Two premium picks (defined as one in the top three rounds such since the draft now is divided into three days, and the final day is rounds 4-7) doesn’t sound like a lot over a 10-year span, but without a frame of reference it’s hard to know for sure.

So here is the frame of reference:

Pro Football Focus ranked all 32 NFL offensive lines heading into training camp in the 2016 season. I took a look at the top 12 teams to see what they have invested in the top three rounds of the draft during the same 10-year time frame as the Vikings — while also looking to see how much each team has invested in the past four drafts, when the Vikings haven’t drafted any O-linemen in the top three rounds. Here are the results:

The average of the 12 teams: 4.7 offensive linemen drafted in the first three rounds of the last 10 drafts, and 1.8 in the last four years.

Now: this isn’t to say all the picks have panned out. But it does show a definite gap in commitment to choosing linemen in the top of the draft between those teams and the Vikings.

The Vikings’ strategy, instead, has been pretty clear: choose players at more athletic skill positions on offense and defense in the early rounds while trying to bolster the offensive line by hitting on late-round projects.

Can you guess how many offensive linemen the Vikings have chosen in rounds 4-7 of the last 10 drafts?

A whopping 11, including SEVEN in the last four drafts. One can be considered a major success: John Sullivan, chosen in the sixth round in 2008, was a very solid starter until his health betrayed him. Brandon Fusco, a sixth-rounder in 2011, has started 59 career games with the Vikings. T.J. Clemmings, a fourth-rounder in 2015, has been pressed into action each of the last two seasons with mixed (at best) results. The rest largely have been non-factors to-date.

That led the Vikings into the free agent market this past offseason, where they grabbed Alex Boone and Andre Smith. Those additions, it should be noted for an apples-to-apples comparison, were enough for PFF to rank the Vikings’ offensive line No. 15 entering this season — not great, but squarely middle-of-the-pack and hardly a disaster.

PFF concluded: “This is a line that, if everyone is at their best, will be very good; if not, it will be below-average.” The latter has played out because of injuries and less-than-expected depth.

That said, the Vikings were in the position of hoping for the best because of their draft strategy. In the last four years, the Vikings have used No. 1-3 round picks on: one QB, two WRs, one RB, three DBs, three defensive linemen and two linebackers.

Those eight defensive players helped fuel last year’s 11-5 season and were the backbone of this year’s 5-0 start. But the shortcomings of the offensive line, more than anything, are threatening to derail this season.

As Mark Craig wrote today, the Cowboys have taken the opposite approach and are thriving behind a fantastic offensive line. It’s something the Vikings will need to remedy in future drafts — but that doesn’t do them any good in 2016.