Tamim Iqbal is the first Bangladesh batsman to score 6000 ODI runs. In the 11 years he has taken to reach the milestone, Tamim has gone through many changes in technique and become a more mature cricketer. Here's a breakdown of his development as Bangladesh's most successful batsman:

0 to 1000 runs: The baby steps
Tamim's introduction to international cricket essentially came through his half-century against India in the 2007 World Cup. Some saw it as a seminal moment for him and Bangladesh cricket. The win effectively got Bangladesh past the group stage for the first time in a World Cup, but for Tamim it turned out to be his only thrilling outing. He averaged only 15.12 in the other eight World Cup games that year.

By his own admission, Tamim got figured out by bowlers because he had only a couple of shots in his arsenal. For instance, he was not good at timing balls off his pads. Exactly a year after his debut, Tamim made his maiden ODI hundred and later in 2008, he would reach 1000 ODI runs in 37 innings.

1000 to 2000: Jamie Siddons' project
In 2008, Bangladesh's coach Jamie Siddons took Tamim under his wing. Hours in the nets with Siddons helped Tamim learn how to play on the leg side, leaving deliveries that weren't worth chasing, and how to build an innings. That, however, took time: Tamim went six series without making 100 runs in any of them.

Finally, against Zimbabwe in August 2009, Tamim broke free. He made over 300 runs in five ODIs, including 154 in Bulawayo that helped Bangladesh chase down 313. That 154 is still Bangladesh's highest ODI score.

2000 to 3000: The first hot streak
Between January 2010 and August 2011, Tamim found rhythm. He not only made 1000-plus runs in ODIs, he made 895 Test runs at an average of 55.93. He took advantage of field restrictions and found ways to settle down on most days. Still, Tamim was unable to convert his fifties into hundreds. Technique wise, Tamim drove more freely and started to develop the Calypso-style pull shot. But there remained holes in his game, especially after he passed the 50-run mark.

This period was also memorable for his Test hundreds against India and England, and also for his swift elevation to the vice-captaincy.

3000 to 4000: Slim pickings
The three and a half years that Tamim took for these 1000 runs came with many lessons on and off the field. It started with him losing the vice-captaincy after a dismal tour of Zimbabwe in 2011.

And then, after a poor spell against West Indies and Pakistan at home, Tamim was dropped for the 2012 Asia Cup, only to be reinstated after the Prime Minister's intervention. He responded with four fifties, but there was no ground-breaking performance in ODIs or Tests between 2012 and 2014.

Out of form, Tamim became agitated on and off the field. He was impatient as an opener, often throwing away starts. He also took internet trolls far too seriously. The pressure grew on him during the 2015 World Cup, where he scored an important 95 against Scotland in a big chase.

4000 to 5000: Man on a mission
After the 2015 World Cup, there were noticeable changes in Tamim's physique and attitude. He became fitter and, according to many who dealt with him in the team, had cleared his hurdles. He struck twin hundreds against Pakistan, as well as a maiden Test double-hundred, and became a more consistent batsman. By October 2016, Tamim became the first Bangladesh batsman to score 5000 ODI runs.

5000 to 6000: Rapid consolidation
A fitter Tamim took it up a notch in both Tests and ODIs. He slammed a match-winning hundred in Sri Lanka, which came after a match-winning effort in the fourth innings, in Bangladesh's 100th Test.

The 2017 Champions Trophy was Tamim's first successful ICC event - 293 runs in four innings. He also made match-winning contributions in Tests against England and Australia during this period. He missed the ODIs in South Africa but in the 2018 tri-series, he made a resounding start with two scores of 84.

Tamim has evolved into a batsman who strives to give his team stability in the first Powerplay, and then looking to play the long innings. He lets those around him score at a rapid pace, and accelerates only after passing 50.

In the process of becoming the first Bangladesh batsman to 6000 runs, in Mirpur, Tamim also became the highest ODI run-scorer at a single venue. He went past Sanath Jayasuriya's tally of 2514 runs at the Premadasa.

Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84