Here, the PA news agency takes a look at England's record in their 36 Tests with the Yorkshireman as captain.
Jekyll and Hyde England
Root's win-loss record as England captain actually stands up reasonably well among England's recent captains.
His 47.2 per cent win rate is bettered only by Michael Vaughan (51 per cent) and Andrew Strauss (48) among England's last six long-term captains – excluding Marcus Trescothick's one win in two Tests.
If his side are unable to force victory, though, their lack of draws becomes a striking concern with just four – or one every nine Tests.
His 17 wins and 15 defeats exactly match Nasser Hussain's record – but the latter was in charge for 45 Tests, 25 per cent more than Root at this stage, and oversaw 13 draws.
Root and new coach Chris Silverwood spoke ahead of the winter tours of New Zealand and South Africa of the need to occupy the crease – but they lost six wickets for 76 in an innings defeat to the Black Caps at Mount Maunganui while in Centurion, their last seven wickets contributed just 39 in the first innings and 64 in the second.
A recurring issue
That first innings of 181 was also the 17th time Root's England have been bowled out for under 200 since he took charge in the summer of 2017.
Nine of those have come on home soil, including three at Lord's and two each at Trent Bridge – where they also made 205 all out against the Proteas – and Edgbaston.
It is in marked contrast to only seven scores of 400-plus – though credit should also be given for three declarations with 350-plus on the board and, of course, the Ben Stokes-inspired 362 for nine in August's win over Australia at Headingley.
England's average score per wicket under Root stands at 29.2, meaning their average "completed" innings of 10 wickets would yield only 292. Root and Andrew Flintoff (298) are the only England captains this century to see that figure fall below 300.
Skipper's average shows the strain
The toll taken by the captaincy on Root's own batting is also now becoming obvious, with his average fully 10 runs lower when he is skipper – 42.53, compared to 52.80 in innings before he was appointed.
His much-discussed problem converting fifties into hundreds has played a part in that – before taking the captaincy, he had 11 hundreds and 27 fifties in 53 Tests.
Having been captain for 36 matches, 68 per cent of his pre-captaincy tally, his rate of half-centuries has held up – he has 18, or 67 per cent of his previous mark.
His six centuries, though, represent just a 55 per cent return compared to what went before – a clear drop-off in the context of the other figures.