This is mostly an NFL thing, though I see it on the college level, now and then.

Wherever it is allowed, it is objectionable.

That would be the four-five-six-etc.-man clot of players who push their way into what usually begins as a one-on-one, open-field tackle and ends as something rather like a rugby scrum.

(Here is a good — that is, bad — example of it in the NFL.)

It is bad football, and it also can lead to injuries. It is time for the NFL to step in and ban it.

This was note yet a “thing” when I left the U.S. for the UAE in the fall of 2009.

It certainly is now.

You have seen it. Player X carries (or catches) the ball … Defender Y stops his momentum with a waist-or-higher semi-tackle. Player X does not go to the ground so the play, under current rules, remains live.

As it turns out, NFL defenders clearly are coached in this way: First man stops Player X. Second man makes sure Player X is held up so that he (and the third and fourth defender on the scene) can spend a good long while trying to rip the ball out of the hands of the surrounded Player X.

More than once in a while, they are successful, and a “fumble” develops quite some time after forward progress has ceased but before Player X touches the ground.

Another part of this also is objectionable, and rugby-like. In some cases, other players on offense rush to the site of the ball and try to push their teammate, Player X, deeper into the opposition’s side of the field.

When both teams are fully committed — defenders holding up and grabbing the ball, players on offense trying to push the whole clawing mass forward — nine or 10 players might be involved. (See the video link, above.)

It can also lead to the offense gaining an additional four or five or eight yards before someone (finally) stumbles and the whole of the scrum finally goes to the ground.

This is ugly and stupid and dangerous. It is several moments of several plays in just about any game that have nothing to do with modern football; they are regressions to primitive rugby stuff from ages past.

Meantime, the original player, Player X, is coached to try to get another yard or two when he clearly should go to ground as soon as possible — to avoid being jumped by two or three more defenders keen to snatch the ball. A tactic coached, clearly, by every defensive coordinator in the league.

It leads to after-the-fact fumbles. It leads to ridiculous scrums of players pushing a now-helpless and squished Player X.

It also can lead to injuries as all these late-comers slam into the original player and the first-contact defender.

The NFL needs to look at this asap, because this is a form of sanctioned cheating — the attempt to steal the ball from the man carrying it … while the latter’s teammates try to push him to a yard line he never would have reached, otherwise.

Officials need to blow their whistles the moment forward momentum by the ball-carrier (our Player X) is halted — do not wait for the man to go down, because he often is being held upright by the first defender who is counting on his teammates to come on by and try to force a fumble.

And everyone arriving late to the scene should be at risk for a “late hit” flag.

Every player involved is trying to gain an advantage in a standing-up version of the fumble pile — which at least does not move five or six yards in one direction or another.

If the NFL can’t figure this out, then it may as well throw out the helmets and shoulder pads and just get on playing rugby — because it certainly looks like that game with the stubby ball and lots of cauliflower ears.