'We haven't got everything right. I haven't got everything right as a coach and I put my hand up for that.'
Brendon McCullum admitted he had made mistakes as England head coach and said their preparations may have been flawed after the tourists surrendered the Ashes with defeat in the Third test in Adelaide on Sunday.
England's light preparations and lack of tour matches in Australia drew heavy criticism from former players and pundits, and the subsequent Ashes failure has put McCullum's role under major scrutiny.
"It is disappointing when you lose and I'm sure there will be plenty of questions asked and rightfully so," McCullum told BBC Test Match Special after England's 82-run loss at Adelaide Oval.
"We haven't got everything right. I haven't got everything right as a coach and I put my hand up for that."
England had one intra-squad match with the England Lions in Perth and opted against further match practice following defeats in Perth and Brisbane.
Their preparations were similar for other tours, including to India and Pakistan last year.
"I have been very strong about the conviction we had and our preparation," McCullum said.
"For us, it was a matter of trying to replicate what we have done in series that have been successful for us away from home.
"Maybe we didn't get that right and I'll acknowledge that.
"Ultimately you are responsible for how you get your side ready and how you prepare them.
"We are 3-0 down so you would probably say there was room for change there."
McCullum said England had played much better cricket in the last two days in Adelaide but conceded the tourists had been outplayed in all facets of the game.
"Credit goes to Australia. They have been as precise as a team as I have seen in the last few years. They put us under pressure throughout," he said.
"We only had fleeting moments in the last three Test matches where we felt like we were on top.
"You accept that and you try to work out ways you can work and identify things you need to make sure to polish up on to give yourself more chance."
The fourth Ashes test starts on December 26 in Melbourne.