Can they make their most successful year in international cricket even better?
By beating South Africa 2-1 in the ODI series last week, Bangladesh propelled to a different stratum of performance and answered the question asked of them at the end of their 2-1 ODI series win over India. Between 2002 and 2011, Bangladesh dreaded playing against South Africa, losing 13 out of the 14 ODIs they played in this period. But in the space of five days, not only did they fight back from three demoralising losses in the T20s and first ODI, they dominated a dominant force.
As their international schedule stands now, Bangladesh have no more ODIs in 2015, and will play in the format again only during a five-match series against Zimbabwe early next year. The BCB is trying to persuade West Indies to play three ODIs and three T20s in November this year, but negotiations are still ongoing.
If the South Africa ODI series was indeed their last of 2015, then Bangladesh should be proud for recording the fourth-most ODI wins in the first six-and-a-half months of the year, and also for ending with the third-best win/loss ratio behind Australia and New Zealand. The 2-1 series win against South Africa also cemented their place in the 2017 Champions Trophy.
The manner in which Bangladesh engineered the turnaround against South Africa was quite simple, but someone had to sit down and do the straight-talking with a team that lost three games in the space of a week.
Mashrafe Mortaza had less than 48 hours to turn around from being 1-0 down on July 10. Coupled with the 2-0 T20 series defeat, there was suddenly some ill-feeling, much of which was unnecessary. Mashrafe held lengthy discussions with the batsmen and bowlers and asked them to remember how they won against India and Pakistan, and repeat it on July 12 and 15.
The bowling attack, which had to be shortened so that they could extend the batting line-up, did the job both times. It was up to the batsmen to keep the faith of Mashrafe and the coach Chandika Hathurusingha, who backed the eight-batsman strategy despite it making the playing XI lop-sided and unbalanced.
Soumya Sarkar was questioned about his short stays at the crease, so he worked out how to bat till the end. He responded by staying unbeaten in the second ODI, and only getting out with 16 needed to win in the third ODI. His batting on both days showed his different class, particularly when he found the boundaries from acute angles, at times with minimal footwork. Mahmudullah, returning to the side from a finger injury, helped Soumya in the second game while Tamim Iqbal played second fiddle to Soumya in the series decider.
Mustafizur Rahman, the star of the series against India, and Soumya will both have to guard against complacency as they are still in their first year of international cricket. Sabbir Rahman and Litton Das are similar young players, but have more to work on their individual games. Among the seniors, Mushfiqur Rahim has gone through a bit of a trough in form, but he is allowed one after batting through more than four years without much of a dip. He now has a bigger role to play in the two Tests against South Africa.
The focus of the BCB, henceforth, should be to maintain a healthy diet of international cricket for their marquee product: the Bangladesh national team. The success of 2015 is, they say, the best time to find more tours and invite more teams. The BCB president, meanwhile, can take a little credit for his sermon before the turnaround but it would be wiser not to take such things too seriously. His job, as big as it is already, should focus on cricket diplomacy that brings them more matches.
There will still be critics who will pick holes in Bangladesh's performance in 2015, that England were lackluster in the World Cup, Pakistan fielded a sub-standard side due to transition, Mustafizur gave a once-in-a-lifetime performance against India, and South Africa were weakened without AB de Villiers.
If South Africa are deemed weaker without their ODI captain, it does not put the rest of the team including Hashim Amla, Faf du Plessis and Morne Morkel among others, in good light. As Mashrafe said, even Australia would have been happier to face South Africa without de Villiers.
India were undone by a newcomer's novelty delivery, but the same bowler was consistent against South Africa in five games. Pakistan too would have taken advantage of a side in transition while at the World Cup, Bangladesh showed that the gap between the big teams and them is starting to close down.
Bangladesh have several ODI highlights in 2015. Mahmudullah's twin hundreds at the World Cup, and Mustafizur taking eleven wickets in two matches definitely stand out. But more than everything, conquering the sub-continent kings and an international bully will put Bangladesh cricket in a different plain, and hopefully readjust the perception of the rest of the cricket world.

Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84