Trevor Bayliss believes a reduction in the number of first-class counties could help England bridge the "huge gap" between county and international cricket.
Victory at The Oval ensured England maintained their unbeaten home series record in Test cricket under Bayliss' five seasons as head coach, though he will probably be remembered best for coaching the side to their maiden World Cup victory earlier in the year.
But in a wide-ranging exit interview with ESPNcricinfo, Bayliss has questioned "whether the county game is producing the players we need" and suggested a reduction in the number of teams from 18 to ten in a bid to improve the quality of competition. He also feels the quality of county pitches must improve if developing players are going to be given the best opportunity to prepare for the higher level.
"You have to ask whether the county game is producing the players we need," Bayliss said. "Is the competition underneath [the England team] doing the job it should be? There's a huge gap between county and international cricket. Huge.
"Again and again, we've picked the best players in the county game. And again and again, they've found the gap too large to bridge. Our top players come back from county cricket and they're not complimentary about the standard. They don't think it helps prepare them for international cricket.
"The pitches are soft and damp. So bowlers get far too much assistance and batsmen don't get into the habit of building long innings. Those same bowlers then come into Test cricket and they find the pitches do almost nothing and the ball won't swing round corners. And the batsmen find the pace of the Test bowlers a shock.
"If you had better pitches - pitches that offered less to bowlers - you might start to see some fast bowlers developing. You might see more spinners developing. You might even see some better slip catchers because I think the big problem in English cricket is concentration. Players have forgotten how to concentrate for long periods of time. They just don't have to do it at county level.
"I'm not criticising groundsmen. They have a tough job, because there's too much cricket and the Championship starts in early April.
"But no one seems to want to get their head down and guts out a score. The attitude seems to be, 'I'd best get on with it before an impossible ball comes along.' But maybe that's partly because society has changed. Everything is quicker now.
"The ECB and the counties have to pull in the same direction. There has to be a collaborative approach ensuring that England is at the heart of it. Ultimately, a successful England team, across all formats, will naturally benefit the game at county level and even have a positive impact on grassroots.
"I think there are too many teams. If you had fewer - maybe ten - the best players would be in competition against each other more often and the standard would rise. I think you'd see tougher cricketers develop. Cricketers who are better prepared for the Test game.
Bayliss also expressed his incredulity over counties offering stints to overseas players who will, later in the same season, use that experience in Test series against England. Marnus Labuschagne, for example, prepared for the Ashes by representing Glamorgan and adapted to conditions so well that he finished the series as Australia's second-highest run scorer.
"I find it incredible that Marnus Labuschagne, Peter Siddle, Cameron Bancroft, James Pattinson and the like are invited over to play county cricket ahead of an Ashes series," he says. "There's no way Australia would allow England players to acclimatise in the Shield ahead of an Ashes series. And quite right, too. I think the ECB should have a look at that.
Bayliss he suggested there should be more knockout cricket at age-group level to help prepare players for high-intensity moments in the professional game. "Australian cricketers are tough and robust. They come up through a system which prepared them for Test cricket. From age-group cricket into club and Grade cricket, they play semi-finals and finals. So they get used to played knock-out cricket. They get used to playing under pressure. I think England could do with more of that.
Read the full interview here