Can't relax in crunch games

Both of Bangladesh's series against West Indies this year went down to the deciding match, and on the day of the decider Bangladesh were switched on right through the game. Tamim Iqbal stayed at the crease for 38.5 overs of the innings to score 103 in August while on Friday Mehidy Hasan grabbed four wickets to ensure the opposition couldn't even get to 200.

There were two other deciders in 2018, but Bangladesh let things slip on both occasions. Against India in the Asia Cup, the middle order couldn't capitalise on the 120-run opening stand. And against Sri Lanka in a tri-series final, they failed to back up a good bowling performance and, with Shakib Al Hasan absent, they were 142 all out in a chase of 222. This 2-2 record in tournament deciders could have been 4-0 had they been a little more careful.

Saifuddin, an improved cricketer

Mohammad Saifuddin wasn't considered to be in the reckoning after the hidings he received from David Miller and Darren Sammy in 2017. But since his return to the ODI side against Zimbabwe in October, he appears to have become a more patient cricketer. He has bowled better in the death overs and, more importantly, hasn't overused his variations.

He has also been keen to set his own fields, which was evident during the third ODI against West Indies. And his batting appears to have improved too, with him having seen the value of thinking like a proper batsman rather than modelling himself after a pinch-hitter.

Mehidy has a role in ODIs

Mehidy has been a match-winner in Tests ever since his debut in 2016, but it has taken him an extra couple of years to crack one-day cricket. He targets the stumps more often now and at a quicker pace, tactics that have helped him become one of the most economical ODI bowlers in 2018 (minimum 100 overs bowled) He has also been a handy batsman and an agile fielder - all of which make him a good bet to be on the plane to New Zealand and England.

Batting is still reliant on four seniors

Tamim, Shakib, Mushfiqur Rahim and Mahmudullah have scored 56% of all Bangladesh's runs off the bat in 2018.

The inconsistent displays of the other batsmen have prompted the selectors and team management to keep chopping and changing. Imrul Kayes, for example, was dropped two matches into the West Indies series after having scored 349 runs against Zimbabwe in the previous ODI series.

Liton Das made a hundred in the Asia Cup final but has been erratic since then. The same can be said about Soumya Sarkar, while Anamul Haque, Sabbir Rahman, Mosaddek Hossain, Najmul Islam Shanto, Mominul Haque and Ariful Haque find themselves way behind in the queue for spots in the batting order.

The need for a settled top-order

There is still no clarity on who will partner Tamim at the top of the order, although Liton is perhaps the best fit. A strong strokeplayer, he also provides Bangladesh with a left-right combination. He'll need to be more consistent though. Soumya batted at No. 3 in the last ODI of the recent home series against West Indies and it is possible he will continue to do so, with Imrul slowly slipping out of contention for a place in the XI.

Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84