He doesn't.
The argument is that when you equalise all other factors there isn't any evidence that a manager doing his coaching, tactics and all that nonsense is any bettered worse than anyone else.
Both Chelsea and us improved because of the money spent. Not the manager.
In Chelseas case both Rafa and Di Matteo won exactly the same number of average points per game, working in almost indentical circumstances. It's the strongest point in support of the argument. (Which is not a controversial point, but a proven statistical fact)
But the managers don't only manage league games. For example:
Benitez
Di Matteo
Unbeaten in 68% vs Adkins’ 54% (56% of games against top 10 sides vs 50% during Adkins’ reign), GD -1 vs -10 despite close PPM stat
Lost VDV, Modric – 80 apps, 18 goals, 15 assists
11/12: 3rd in Europa League grp stage, League Cup 3rd round, FA Cup semis
12/13: Europa League Q-finals, League Cup last 16, FA Cup 4th round. Tottenham's 72-point Premier League tally is their highest ever.
Lost Carroll, Bellamy, Kuyt, Rodriguez, Adam – contributed 184 appearances, 31 goals, 28 assists the previous season
Of the money spent: Borini’s injuries (Sep, Oct, Feb) = stop-start season, Coutinho & Sturridge only arrived in midseason. These 3 (31m) = 64% of the money spent half/under-utilized
1st season in 1st team management. Record points haul in the Premier League. Only manager spent was on Ben Foster. (And would 17 goals Lukaku have moved there had it not been the Clarke factor?)
11/12: League Cup 2nd round, FA Cup 4th round
12/13: League Cup winners, FA Cup 3rd round
This after losing Sigurdsson, Caulker, Sinclair, Allen – 124 apps, 19 goals, 15 assists. How's Michu for a signing
11/12: League Cup 3rd round, FA Cup 4th round
12/13: League Cup semis, FA Cup 4th round
Average squad age down from 28 to 24, slashing the wage bill in the process too. Is Benteke not Lambert’s find? And surely his value would’ve tripled now?
Before everyone starts to write these clubs off for next season, just think about what they have done. Could Wenger, Benitez or Mancini have done that with the players those three had last season?
If you put Mackay, Bruce and Holloway in charge of Manchester City, Chelsea and Arsenal next year they would still finish in the top four because it’s the clubs which have got them there.
It’s not really about who has managed them. The clubs with the most money generally have the best players, the best facilities and the best set-up.
Last season’s top seven will be next season’s top seven. It’s sorted already barring a miracle.
A 60,000 seat stadium with the debts almost gone. Owned by a multi-biilionaire and have a big corporate concrete bowl for a ground.
Constant CL football year after year. Without ever winning it. Ever.
Finishing above their local rivals. Who never win anything or challenge for the title.
I think I'd celebrate like we'd won a trophy if we ended a season in that position any time soon.
Fuck Arsenal.
Harry Redknapp on promoted club's British managers.