The third goal West Brom scored against Arsenal is being marketed by the papers as a testament to Arsenal’s failures: the players didn’t try, they weren’t tough enough, and the manager didn’t organize them well enough. All of that is true AND the goal should have been disallowed.
In the first clip we see how Arsenal are set up. This is a huge problem in the making because you have three of Arsenal’s least powerful players (Bellerin, Ox, and Ramsey) guarding three of West Brom’s most direct aerial threats. Meanwhile a clump of Arsenal defenders (Mustafi, Welbeck, Koscielny, and Nacho) are busy guarding nothing and someone is tussling with a West Brom player behind Ospina.
Here we see the three West Brom players who will eventually make a move for the header. The space has opened in front of Bellerin. Note that Ospina is struggling with a West Brom blocker.
Ramsey stops his run, effectively not marking anyone. Ox is shoved out of the way (note that the referee is looking right at that) by Dawson. And Bellerin actually takes a step BACK out of the fray. All the other Arsenal defenders have been pulled out of position. Ramsey and Bellerin in the zonal system are supposed to attack that zone. They don’t. They have given up on this defensive play. Note also that Ospina is now completely blocked off by a West Brom player. The only guy who could get to the ball, can’t.
And when the ball arrives, Ospina is trapped (illegally) and the ref should have called the play dead. But also notice that there are zero Arsenal players attacking the zone where the ball arrives.
For me, the English game needs to be better at recognizing this cheat tactic that Pulis and his team deploy of shielding the opposition goalkeeper from getting into the play and also the Arsenal players should all be docked a week’s wages for not even attempting to challenge for this ball.