In years to come, it is likely that few will remember the Bank Alfalah Presents the Mobilink Jazz Cup Series particularly warmly. It was, after all, just another series in an overcrowded schedule contested by two middle-ranked sides taking their first steps on a road that leads to the 2015 World Cup.

But, should either one of these sides go on to lift that trophy, perhaps they will reflect that it was the seeds sown in the course of these four games that bore fruit.

England, in particular, have made demonstrable progress over the last couple of weeks. Despite their debacle in India, England have now identified a squad of players that they believe can serve them over the next few years and develop and improve in the process. This was their first clean sweep against a major Test-playing nation since 2008, when they defeated South Africa with one game lost to rain. England have now leapfrogged Pakistan to go fifth in the ICC ODI rankings.

More importantly, a few issues have been resolved. The opening partnership of Alastair Cook and Kevin Pietersen now appears to have been set in stone; Steve Finn has emerged as a seamer capable of leading the attack alongside the likes of Stuart Broad, James Anderson and Tim Bresnan; while Ravi Bopara, Craig Kieswetter and Samit Patel also contributed.

Pietersen's success was the most eye-catching. Coming into this series he had struggled for form for some time: he had made just three half-centuries in his last 36 ODI innings and had not made a century since November 2008. His promotion to an opening position looked like the last throw of the dice.

How quickly things can change. Now, after two centuries in succession, he might just be back to his best. This was an immensely impressive performance. It was not just that it was his longest innings, his highest innings or that it brought him level with the record held by Graham Gooch of 28 international centuries for England, it was that he did it with his side under pressure. From 68 for 4, it took great composure and skill to time this chase to perfection. He later rated it "probably the best" ODI innings of his career. It is hard to disagree.

They must improve their fielding. It is rare that Pakistan cling on to a 50-50 chance. Julien Fountain, who will shortly be appointed as fielding coach, has his work cut out.

Cook was scarcely less impressive. He has taken huge strides as a leader and a batsman in the last few days and has merited his man of the series award and his call-up to the England T20 squad. All doubts about his position are surely dispelled.

Perhaps most reassuring from an England perspective was their "bench strength". England made four changes for this game, with their three senior bowlers - Graeme Swann, James Anderson and Stuart Broad - all rested and Ravi Bopara's sore back ruling him out of contention. While Jos Buttler endured a tough baptism, Danny Briggs, Jade Dernbach and Tim Bresnan all bowled impressively. Young men, even young men so extravagantly gifted as Buttler, do not come with guarantees. But he and Ben Stokes still have every chance to force their way into the 2015 reckoning. They are too good not to come again.

Craig Kieswetter also impressed in the final game. His keeping is still not as polished as he would like, but it has improved and will continue to do so. England have invested a great deal of time in Kieswetter. Now is not the time to abandon the plan.

There was a little encouragement here for Pakistan, too. The partnership between Azhar Ali and Asad Shafiq provided a glimpse of their future direction, while Adnan Akmal, too, provided some stability behind the stumps. Yes, Azhar might have to develop his range of strokes, but in a side that struggle to bat through their overs, his solidity is not to be dismissed.

They have more concerns, though. The balance of this side, with five spinners and just one seamer, might be useful for pitches here, but it will be of little use in Australia or New Zealand, where the 2015 World Cup will be contested.

The batting is fragile, too. They were bowled out in all four of these games and have reached 250 only three times in their last 29 ODIs. Their highest run scorer, Misbah-ul-Haq, is also the oldest player. Aged 37, he is unlikely to make it to the World Cup.

What was the difference between their Test form and their ODI form? Well, in the Test series, Pakistan were able to grind their way to match-winning totals. The likes of Misbah and Azhar could take their time without the pressure of overs ticking away. They were able to play obdurate, attritional cricket. That option is denied them in this format.

Most of all, they must improve their fielding. It is rare that Pakistan cling on to a 50-50 chance and, in their coach and captain's estimations, England improved fielding is worth anything up to 50 runs a game. Julien Fountain, who will shortly be appointed as fielding coach, has his work cut out. He is not an alchemist.

"England improved; they really batted well after the Test series," Misbah said afterwards. "Their top order was the big difference. It is remarkable to score four centuries in four innings. That was the main difference."

George Dobell is a senior correspondent at ESPNcricinfo