Who is the most successful coach in men's T20 today?

When Liverpool FC hired Arne Slot as their new manager, many of their supporters would have known very little about him. Some would have read newspaper articles explaining his background, others would have done the research themselves, using football's vast statistical databases to learn more about him.

Finding out where his last club, the Dutch side Feyenoord, finished in their league last season is straightforward enough, but it is not much harder to find out - using the free website Transfermarkt - that Slot averaged 2.15 points per game across his tenure; or that his average points per game across his career makes him the Dutch league's fifth-most successful manager.

There is a misconception that cricket is a sport saturated with statistics, but in practice, it rarely is. In the equivalent scenario - a T20 franchise hiring a new head coach, say - tracking down their career record is almost impossible. ESPNcricinfo does not keep records of coaches' win percentages, and there is a scarcity of publicly accessible data.

It is left to a few analysts to keep their own individual databases. These include CricViz's Kieran Parmley, who has worked with Desert Vipers and Islamabad United. He has logged head coaches' records across more than 2000 T20 matches spanning the ten major short-form leagues* over the past six years. Parmley kindly shared his data set for this article, and the details are intriguing.

Franchise cricket has created a group of players who travel the world, jumping from one league to another at short notice. Alex Hales, for example, has represented 11 different short-form teams in the last year. For coaches, the demands of the job - and the need to commit to an entire tournament - mean the picture is a little different: there are only a dozen men who have spent at least one season as a head coach in three or more of Parmley's top-ten leagues since the start of the 2018-19 season.

T20's inherent volatility and the mechanisms that most leagues have in place to ensure competitive balance - annual drafts or auctions, plus strict salary caps - mean that most of those 12 coaches have similar numbers of wins and losses. There is one outlier at either end of the scale: Andy Flower (W101, L68) and Trevor Bayliss (W49, L69).

Flower only joined the franchise circuit in 2020 after 12 years at the ECB but has been involved in five major leagues - PSL, CPL, IPL, ILT20 and the Hundred - and has won titles in three of them (PSL, the Hundred and ILT20). He also has a remarkable record of taking his teams into the knockout stages, only failing to do so in two of the 15 seasons he has overseen in total.

It invites an obvious question: what sets Flower apart from other T20 coaches? He has finally started to shake off the tag of being "intense" that he gained during his tenure with England from 2009 through 2014; now, the word that comes up most often in conversations about his coaching style is "thorough".

"Wherever he goes, there's success," Lewis Gregory, who has worked closely with Flower as Trent Rockets' captain, says. "You can see why: he's very diligent with the preparation and work that he puts in before a game, and he's constantly testing guys in training to get better - whether that's about small margins, working on new shots, or just simple things about their game plan."

It all starts in recruitment. Flower is renowned for extensive preparation ahead of drafts and auctions. His teams often feature multi-skilled players. "I have read that occasionally, about me going for a bank of allrounders," Flower told me in 2022 , when he led Trent Rockets to the Hundred title. "It's not as black and white as that, because each recruitment situation is different."

But he places substantial value on batting depth, generally preferring to pick a genuine allrounder at No. 8, as well as looking for a mix of left- and right-handers. "There's no doubt that, as a batter, when you look down the order and see that you bat to No. 9 or 10, you feel a greater sense of freedom to attack," Flower said.

He also looks to provide "maximum flexibility" for his captains. "It's likely that someone will be hit or have a bad day," he said. "You want that extra bowling option… and if that sixth bowling option turns the ball in a different way - or angles the ball in a different way, as a seamer - to the rest of your bowling attack, that's really useful."

Perhaps the biggest challenge for the franchise coach is to get a disparate group of players pulling in the same direction. Many T20 teams have only existed for a few years - especially given the rapid recent growth in the number of leagues - and operate in a low-stakes environment, without major demands on performances from established supporters.

In many cases, the job title - "coach" - is a misnomer. While there are some exceptions - some IPL teams have long training camps, and counties in the T20 Blast have their players under 12-month contracts - players tend to report a couple of days before the start of the season in most leagues. It means that there is little time for hands-on, technical coaching over the course of a season: in practice, many coaches act more like managers.

The onus is on the coach, therefore, to instil a team-first culture. "We all know what it's like to be in a poor environment, where people are out for themselves and not actually aligned to where the team wants to go," says Sam Billings, whose Oval Invincibles side are back-to-back winners of the Hundred under Tom Moody 's stewardship.

"In the first two years, we disappointed ourselves really - we didn't really play to our potential. After that we recalibrated, and that's where Tom Moody was absolutely instrumental - a cultural architect, so to speak. Just getting that real alignment collective is so key… There's a lot of good teams in this competition, but those things off-field, they pay dividends on the field."

At the start of the 2024 SA20, Sunrisers Eastern Cape's head coach, Adrian Birrell , sat his squad down and told them to learn the names of staff working at their home ground in Gqeberha. "You're flipping competitive on that field, but you're actually nice people off the field - otherwise, I don't want you in my team," he said. "It's as simple as that." It highlighted the value of recruiting the right people, not just the right players.

For some time, Daniel Vettori was cited as an example of a coach who had been given more opportunities than his record demanded on the franchise circuit, having struggled in roles with Royal Challengers Bangalore, Brisbane Heat and Middlesex. But this year, on his return to the IPL, after working as Andrew McDonald's assistant for Australia, Vettori's Sunrisers Hyderabad were trailblazers, making three 260-plus totals and reaching the final .

"Dan's one of the best out there," says Moeen Ali, who has worked with Vettori at RCB and Birmingham Phoenix. "His strengths are his sense of the game and his demeanour generally: knowing when to speak, when not to speak, when to say the right thing. And he's fun. He's right up there with most of the Kiwi coaches - with Baz [McCullum] and Flem [Stephen Fleming]."

Aside from the most regular globetrotters, a handful of coaches have exceptional records in a single league. These include Mohammad Salahuddin (Comilla Victorians), Thilina Kandamby (Jaffna Kings/Stallions), Jason Kerr (Somerset), Adam Voges (Perth Scorchers), and Greg Shipperd (Sydney Sixers).

And yet, few of them have gained opportunities elsewhere. Along with the general unavailability of data on coaches' records, it highlights the fact that the T20 industry remains in its infancy, relying heavily on word of mouth or mutual connections. This has only been exacerbated by the rapid expansion of many franchises from a single league to several.

In practice, there are some limitations with the data. Clearly, wins are easier to come by in some leagues than others. Coaches who only coach in the IPL are likely to have worse records than those whose experience comes largely in second-tier leagues. And win-loss records alone do not account for team strength. It is much more impressive to win 50% of games at Punjab Kings than at Chennai Super Kings, for example.

Nor is it the case that the coach is always the man running the show. At Kolkata Knight Riders in 2024, Chandrakant Pandit was officially head coach; in practice, Gautam Gambhir was the man running the show and taking the biggest calls, despite his formal job title being "mentor". At some teams, coaches have to cope with interventionist owners and officials.

It rarely pays to be wedded too closely to the data, and that holds true when it comes to head coaches too. But as things stand, many hires are made without access to any supporting statistics whatsoever. It is better to have limited information than to have none at all.

*The 10 men's short-form leagues considered in Parmley's data are: Big Bash League (Australia), Bangladesh Premier League (Bangladesh), T20 Blast, the Hundred (both England), IPL (India), PSL (Pakistan), SA20 (South Africa), Lanka Premier League (Sri Lanka), ILT20 (UAE), CPL (West Indies)