Louis van Gaal pulled out a dossier full of statistics at his press conference as he hit back at Sam Allardyce's claim that Manchester United are long-ball merchants.
West Ham boss Allardyce described Van Gaal's team as "long-ball United" after they scraped a 1-1 draw at Upton Park on Sunday.
But Van Gaal said Allardyce's "interpretation" was incorrect and the Dutchman produced a pamphlet filled with statistics at his pre-match press conference on Tuesday to support his stance.
The statistics quoted in the A4 pamphlet, which were put together by Van Gaal's analysts, claim West Ham sent a higher percentage of their long passes forward than United during the match.
West Ham attempted 200 passes, according to the figures, and United 343.
The pamphlet said 71.1 per cent of West Ham's "long passes" - of over 25 metres - went forward whereas United's percentage was just 49.9 per cent.
Diagrams in the pamphlet claim to show United's passes went sideways or diagonally, rather than forward.
Van Gaal talks regularly about the fact that he wants his teams to play attractive football.
He was clearly, therefore, annoyed at Allardyce's comments and he had the pamphlet on his desk waiting when he fielded the first question about the West Ham boss' jibe.
"Because I expected this question, I have made an interpretation of the data for this game and then I have to say that it is not a good interpretation from Big Sam," Van Gaal said.
Van Gaal insisted his team only started launching balls forward after 6ft 4in Marouane Fellaini came on in the 76th minute of the draw in east London.
"When you have 60 per cent ball possession do you think that you can do that with long balls?" Van Gaal added.
"Yeah, long balls, in the width, to switch the play. You have to look at the data and then you will see that we did play long balls, but long balls wide, rather than to the striker.
"A ball to the forward striker is mainly caused long-ball play.
"It is not so difficult also to read that.
"I am sorry, but we are playing ball possession play and after 70 minutes we did not succeed, in spite of many chances in the second half, then I changed my playing style.
"Then, of course, with the quality of Fellaini we played more forward balls and we scored from that, so I think it was a very good decision of the manager.
"But, when you see overall the long ball, and what is the percentage of that, then West Ham have played 71 per cent of the long balls to the forwards and we 49."
After reeling off the statistics, Van Gaal rose from his chair and handed the pamphlet to the reporter who asked the question about Allardyce.
The United boss asked the journalist to analyse the last three pages, which contained diagrams which contained coloured arrows pointing in the direction of both team's passes.
"I give you this and you can see that the blue ones are the good ones because long balls are also very difficult, which is why I began with the explanation of ball possession," the 63-year-old said.
"When you have 60 per cent ball possession you cannot play long balls. So again, they did it 71 (per cent) and we 49, and I give it to you, you can copy it and then maybe you can go to Big Sam and he will get a good interpretation."