Just ahead of this ODI series, Eoin Morgan called on his England side to show an ability to adapt to conditions. At the time he made the comment, he foresaw a series played on slow, turning surfaces which could test England's aggressive approach to batting. As it was, most of the series was played on very good batting tracks, with the final match played on a surface offering pretty steep bounce by modern standards.

But the principle was the same: Morgan was calling on his side to show an ability to adapt and they failed to do so. While it would be simplistic to dismiss this England team as flat-track bullies, it wouldn't be totally untrue, either. On flat wickets where the ball neither seams, spins or bounces especially high, England are world beaters.

On other surfaces? Well, they were knocked out of the Champions Trophy by Pakistan on a pitch offering help to spin and reverse swing. They were bowled out for 153 by South Africa on a green surface at Lord's (they were 20 for 6 at one stage) and 196 by Australia on a seaming surface in Adelaide (they had been 8 for 5 at one stage). If they come up against such a surface in a knock-out game at the World Cup - and they did in both the 2013 Champions Trophy final and the 2017 Champions Trophy semi-final - they look vulnerable.

"We didn't adapt," Morgan admitted afterwards. "It was a terrible batting performance which is a disappointing way to end the series. We need to learn from the experience."

The time for learning is up, though. Well, just about, anyway. England will have named their provisional World Cup squad before they play another ODI and they are committed to the batting line-up that played in this series.

They are, in many ways, an admirable bunch. They have improved vastly and expanded the bounds of what we thought possible in this format. On the sort of surfaces which are expected during the World Cup - true, flat and even-paced - they will worry any bowling attack in the world. They have, after all, thrashed the two highest scores in ODI history in the last three years and have four of the five highest totals made in the format since the last World Cup.

And perhaps it is inevitable, if you progress at such pace so often, that you will occasionally fall. For, in the 39 completed first innings England have had in ODI cricket since the last World Cup, they have passed 400 four times and won on each occasion. They have passed 300 on 24 occasions and won 19 of those games. And, yes, on four occasions, they have failed to reach 200 and have been beaten on each occasion. If we praise them for their boldness on the days the shots end up in the stands, we have to be very careful about criticising when those same shots end up in hands. This was a drawn series, after all; not a defeat. They have still not lost a bilateral ODI series (so excluding the one-off game against Scotland) since they were in India in early 2017. That's 10 series with nine victories.

Losing the toss was significant here, too. Perhaps due to heavy rain overnight, the pitch started just a little tacky. With England reasoning it would ease during the day, they felt the need to attack in order to set a winning total. This is not a team that tries to limit the extent of their loss; it's a team that tried to win. Always.

Morgan, to his credit, refused to use the toss as an excuse. Reasoning that winning the toss is always, to a greater or lesser extent, an advantage, he knows that England cannot expect to have things - the pitch, the toss, the conditions - their own way all the way through a World Cup campaign.

"The toss is an advantage across every game we play," Morgan said. "I might have argued that if we'd lost by one or two wickets, but we weren't at the races today."

One of the frustrations with this England side is that it seems, with just a little better judgment, with just a little more nous, they could improve markedly. As Morgan admitted, it was clear from the first few minutes that this pitch offered the bowlers some life and clear that England would have to bat accordingly. For reasons that are not clear, they were unable to do so.

"It was evident from the first two overs [that we had to adapt]," Morgan said. "You could see it from the changing room. We did have that conversation. But we didn't adapt. Trying to curb your natural ability, to try to go from high-risk to low-risk and still get a score in the morning that will be good enough in the afternoon, is difficult."

Whose job should that be to gauge what a winning total is on each pitch? Well, this team has been together for a long time now. Every option for the opening position has played more than 60 ODIs and should be able to show the sophistication to know when to take the foot off the accelerator. Joe Root, too, is an experienced player who has scored more ODI centuries for England than anyone else. He should be able to adapt his game as required. Morgan, with more than 200 caps to his name, should also be able to do so.

Morgan disputes the suggestion that England are slow learners, however. While he accepts there is a general problem in adapting to new conditions, he felt England have shown improvement on slow, low surfaces and simply haven't experienced a pitch with as much bounce in it as this.

"When we come up in conditions for the first time it has gone wrong," Morgan said. "When we've come back in conditions that are similar to where we've made mistakes, we've actually played really well. It's easy to gloss over things like that because when we play well some of our guys make things look quite easy.

"We learned from that Champions Trophy defeat. We went away from home and played on slow, low wickets and improved our game from that experience.

"These was a surface that we rarely come up against. It was just the bounce. And I don't think we dealt and adapted with that. We continued to play as if we were on the same pitch in Grenada. A low-risk shot there was high-risk today."

There are other areas of concern. And the England bowlers' failure to learn to deal with Chris Gayle throughout the series - if anything, he became more destructive as the series progressed - is one of them.

Gayle is an exceptional player, of course. But England will come up against several exceptional players during the World Cup and, if their batsmen get the run-filled pitches they want, their bowlers will have nowhere to hide. They have to find a way to at least stem the bleeding. Gayle hit a six every 8.10 balls he faced this series. It's hard to imagine a World Cup-winning bowling attack allowing that.

Where could they have bowled to him? Well, the Hawkeye pitch map for this innings suggests England attempted to bowl three yorkers at him. The two aimed at the stumps were dot balls, while the one aimed down the leg-side, as Gayle attempted to give himself room, was inside-edged to the boundary. They bowled five yorkers at him during his innings of 162 in Grenada, too. None of them went to the boundary and four of them were dot balls. And they didn't bowl any yorkers on the line of the stumps at him during his innings of 135 in the first ODI. It seems odd that it was not a line of attack pursued more often.

"Gayle is probably in the best form of his life," Morgan argued by way of mitigation. "Our execution needs to be near on perfect and that's a really good test because we are going to come up against similar players in the World Cup."

So, here they are, on the brink of the World Cup and with lessons to learn with bat and ball. They've been the front-runners for this tournament for a couple of years now. But as we get closer to the event, it feels as if the field is starting to close.

George Dobell is a senior correspondent at ESPNcricinfo