Joe Root's bowling is more important than ever and the Australian squad plays into his strengths.

Joe Ruth took two wickets three times in the fourth inning of Ashes' home test victory. Photo: PA/Rui Vieira

Of all the questions England expected to consider before the Ashes, Joe Root's bowling was ranked low. However, with Jack Leach's injury, the ongoing uncertainty about Ben Stokes' fitness, and the ensuing debate over England's offensive line-up, Root's bowling suddenly became quite important.

Steve Smith and Kane Williamson, two of Root's contemporaries, were both utility bowlers in their early Test careers but are now rarely seen with the ball. The root is different. He maintained a useful assist spin throughout his career and made more overs per test — an average of nine — under Stokes than under Alastair Cooke or his own captain.

As a bowler, Ruth has obvious limitations. The best off-spinners find good line and length in one of two pitches; Root does this only for every third. As a result, his 54 test wickets totaled 46.1 apiece.

However, these numbers hide Root's qualities as a non-standard player. With his round arm usually reaching far from the crease and around the gate, Ruth presents an unusual challenge. While he creates a good turn, Root's greatest quality is his drift: on average over his Testing career, he generates slightly more drift than Nathan Lyon.

Root is a bowler who has shown that his best ball can put good batsmen out of play: Shivnarin Chanderpaul and Rishabh Pant have lost to him twice. Like Steve Smith, but only after reaching 200 both times.

Off-spinners tend to be much better bowlers than lefties, but Ruth is unusual in how big his preferences are. He averages 64.9 points against righties in tests, and averages 32.1 points against lefties. Paradoxically, this discrepancy both highlights Root's limitations as a bowler and, when circumstances and opposition are favorable, enhances his value. It is much better to have a part-time worker who prefers one type than a person who is equally modest against both left-handers and right-handers.

Joe Root is much more effective against left-handers, unlike Jack Leach

Root's off-backs are likely to be most valuable against a team like Australia: they have four left-handers in the top seven in Usman Khawaja, David Warner, Travis Head and Alex Carey. Indeed, while Leach has improved against left-handers, Root's performance against left-handers has been strikingly better. In his Testing career, Ruth has averaged 10 runs less than Leach and is only three runs behind left-handers compared to Leach's 3.8.

Bowling Ruta also performed well against Australia. In Ashes Home Tests, Ruth took two wickets in the fourth inning of victory three times — at Lord's in 2013, at Cardiff in 2015 and in the final Test at the Oval in 2019. His 17 wickets against Australia came in pretty decent. 41.2 — On average, if he took 10 wickets, England would be thrilled this summer. #39; Mitchell Marsh on his way to England's 2019 Oval victory. Photo: Action Images/Paul Childs

Thus, under the right conditions, Ruth is an attractive bowling option if two left-handers are in the lead, and a perfectly reasonable bet when one is in the lead. Carey averages just 19.2 against off-spin in Tests, making him the top batsman most suited to Root.

Head has so far excelled at turning the ball away from him in his Testing career, averaging 60.4 against off-spin and Khawaja averaging 49 against off-breaks. But if he survives the new ball, Warner will average a modest 32.5 points against the wrong pin; in all of international cricket he was fired three times by Root at 16.3 each.

Root's bowling could subtly influence England's attack in many ways this summer. The more overs Ruth does, the less Stokes will need. If his bowling game is effective, it will be easier to attack the four sewing specialists, a trick that suits England well, who prefer to bowl at home.

Even if England chooses the spinner, Root's off-spin will still figure in the side's mind. The root's contribution will strengthen the case for choosing a spinner who offers the opposite threat, turning the ball the other way, such as Liam Dawson, rather than another underdog.

While he is far from being a true all-rounder, Ruth may have been a little underrated in his Testing career: against left-handers with an old ball, his out-of-spin would often be a better option than persevering with a right-handed pace.

This summer at Ashes, circumstances and an abundance of southpaws in Australia mean his freelance rotation could be more important than ever before.