For a long time, you wouldn't have associated Bangladesh with the phrase "strong pace attack". A subcontinent team playing on slow, low surfaces, some of which turned, was never going to be big on fast bowling - and Bangladesh wasn't. Kids growing up in the country in the 1980s and 1990s had few fast bowling heroes.
The change was a long time coming. Mashrafe Mortaza and Chandika Hathurusingha, the captain and coach so vitally responsible for Bangladesh's ODI success in the last two years, were firm believers that an aggressive approach would take them to the next level, and were instrumental in Bangladesh beginning to actively picking more pace bowlers in their attack.
It began in 2015
Like all revolutions, this one too was met with resistance initially. Having mooted the idea of employing a four-pronged pace attacked after a careful study of their resources before the ODI series with India in 2015, Mashrafe and Hathurusingha didn't find too many in the BCB's hierarchy who agreed with them. "Risky" was one of the words floated around strategy meetings at the time.
Mashrafe and Hathurusingha are, however, men of conviction.They had faith in Taskin Ahmed and Rubel Hossain, who had done well in the World Cup. Mashrafe himself was fit. Most noticeable was the trust they had in Mustafizur Rahman, who had until then played a solitary T20 international.
The Mirpur pitch too encouraged them; Gamini Silva, the curator, had left a hint of green on. But despite these arguments in favour of a pace-heavy attack, the decision to go with four fast bowlers in the XI came just a few hours before the first game, and was accompanied by much trepidation.
The attack worked well enough for Bangladesh to clinch their maiden ODI series win over India. Mustafizur took 11 wickets out of the 16 that went to the fast bowlers in those first two games. Rubel, Taskin and Mashrafe served too, but a side strain ruled Taskin out of the third game, which forced the team management to take their foot off the pedal.
Apart from one game against South Africa, Bangladesh used three fast bowlers in each of their other five ODIs in 2015. The next year, that trend continued in all but one of nine ODIs. This year, they finally used a four-pronged pace attack again against New Zealand in Cardiff - almost exactly two years since they last deployed a similar attack. During this time injuries to Taskin, Rubel and Mustafizur prevented Mashrafe and Hathurusingha picking four fast men, though considerations of pitches, conditions and oppositions also played a part.
Now, however, it has finally been established that if the pitch and overhead conditions are right, and their bowlers fit, Bangladesh are quite eager to pick a four-man pace attack. And failing that, picking three is the new normal. This is a far cry from the days of their spin-heavy attacks. Just two times since the 2015 World Cup have Bangladesh not used a three-man pace attack.
Four is an army
In the 2015 World Cup, Rubel took four wickets against England and looked the most impressive bowler in the quarter-final against India. He had had an up-and-down international career till then, and had been more successful in ODIs than in Tests or T20s. Even in ODIs, Rubel's troubles in the slog overs and injuries meant that he wasn't always an automatic choice. But his late movement with the slightly older ball always attracted attention.
Taskin, who had made a barnstorming debut against India in 2014, wasn't hitting his stride. But he had pace and was improving his fitness, and in Mashrafe he had a hero he didn't want to let down.
Seeing Mustafizur in the nets convinced Mashrafe and Hathurusingha that India needed to be tackled with pace. It wasn't just that Mustafizur was dismissing Tamim Iqbal and company, but that he was doing it with something unique. He had developed an offcutter, all on his own, that kicked in front of the batsmen, and, when it took an edge, carried to the wicketkeeper.
Bangladesh have tried others, but generally the team management have gone with Mashrafe, Rubel, Mustafizur and Taskin when fit and when presented with the right conditions.
For years Mashrafe and other senior Bangladesh bowlers had argued it is best to use pace in the last ten or 15 overs of an innings. When Mashrafe became captain, this became a guiding principle. An important enabling factor in making Bangladesh evolve from picking eight batsmen in their ODI XI into one that picked four fast bowlers was the all-round skills of Shakib Al Hasan and Mushfiqur Rahim. In those two, Bangladesh have two full batsmen, a front-line bowler and a wicketkeeper. Still, that hasn't always been enough to justify picking four pace bowlers. They needed bowlers who could take wickets.
Mashrafe himself had to work hard to remain fit, but his bowling has improved as he has grown older; he is subtle in his variations and most effective when he can swerve and cut the new ball. His captaincy has ensured that fast bowlers were given a fair run as a collective. When Mashrafe talks, people listen. Hathurusingha, likewise, is inclined to using pace.
A little coaching help
There had been occasions in the past when the need for speed prompted the BCB to hire short- and long-term bowling coaches. Andy Roberts' 2001 stint is usually credited with providing the final push in Mashrafe's elevation into the Bangladesh team. Champaka Ramanayake, Bangladesh's first full-time bowling coach after joining in 2008, is said to have encouraged the selectors to pick a raw Rubel, who reminded him of Lasith Malinga.
Robiul Islam, who had a short stint as the leader of Bangladesh's Test attack, learned to use his first-class experience in Test cricket thanks to Sarwar Imran and Shane Jurgensen. These two fine coaches were also important in Taskin's growth. Jurgensen made sure Taskin played in the 2014 World T20 to get exposure; a couple of months later, he made his sensational ODI debut, with five against India.
Last year the BCB hired Aaqib Javed for a short stint. The bowlers found him to be very well read, and approachable. There remains curiosity about whether Aaqib passed on vital tips on reverse swing, but the bowlers who worked with him were eager for more of what he offered.
When Courtney Walsh joined last year, it was seen as the BCB acknowledging that the team needs a big name to guide them. Walsh agreeing to join was also validation from a legendary fast bowler that this was a pace attack that was challenging enough, with enough potential to work with, for his first international coaching job.
The ones who fell by the wayside
There have been casualties on Bangladesh's road to picking four fast bowlers. Some arrived with big reputations but crumbled in the face of international cricket's relentless pressure, either physically or mentally. There were some whose bodies couldn't handle the day-to-day stresses of bowling for a team that lacked teeth for a long time. A few couldn't handle fame.
Talha Jubair was one of the first whose frail body couldn't take the toll of international cricket. He bowed out early, leaving Tapash Baisya to fend for the team in difficult circumstances. An unheralded pace bowler who had limited skills but a big heart, Baisya fell out of favour as soon as other attractive pace options became available. Syed Rasel didn't last long; Nazmul Hossain succumbed to far too many injuries.
Robiul too couldn't quite replicate his superb Test series against Zimbabwe in 2013, eventually falling out of favour with country, club, and even his division in the first-class competition. Shahadat Hossain served for a while, but he was always seen as someone better suited to Tests (though the numbers don't reflect such a notion).
But in Taskin, Rubel and Musafizur, Bangladesh have an odd combination of bowlers that has clicked.
Taskin is the city boy who became a YouTube sensation even before he played for Bangladesh. Rubel has seen it all, having been on the receiving end when Bangladesh lost the final in his first ODI series, in 2009. His difficulties in Tests, multiple injuries, and a constantly changing action held him back before he came out of his shell in the 2015 World Cup.
Mustafizur too is now realising that the road isn't smooth. Since fully recovering from his shoulder surgery in 2016, he has had good days and bad days. Against New Zealand in Cardiff, his last two spells showed that he was ready to sacrifice his natural ability in order to stop the batsmen from scoring too heavily.
And then, of course, there's Mashrafe, the leader who knows exactly when to praise his charges, and when to deliver a rocket. It is not that he meddles with his young pace attack, but he is close enough to know exactly when to speak to Rubel and Taskin, and when to leave Mustafizur alone to do what he does best.
Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84