Captaincy is the toughest challenge that T20 cricket has to offer and in the Hundred, it becomes harder still: just ask Sam Billings and Eoin Morgan after the tournament clicked into gear with a nip-and-tuck London derby on Thursday night at The Oval.

Billings has earned a reputation as one of the better captains in English domestic cricket, leading Kent to the T20 Blast title last year and soaking up all of the information that is sent his way. In televised games, it is impossible to miss him when he is keeping wicket, constantly tweaking the field, encouraging his bowlers and reminding batters that any given match-up is preying on their perceived weakness.

Morgan, meanwhile, is eulogised throughout the game for his leadership after seven-and-a-half years at the helm of England's white-ball teams. After his international retirement, he has reached a point in his career where he will surely quit the sport as soon as he stops enjoying it, but he clearly still relishes the chance to captain whichever short-form side he happens to be representing.

But the Hundred is a different beast to T20: its format demands that captains make decisions almost constantly, weighing up whether to keep a bowler on for an extra set of five balls. Consecutive sets from each end mean that there is less of a pattern or formula for captains to follow with bowling changes, and dealing in sets of five rather than six means that the tempo and rhythm of the game is significantly different.

Last Thursday night, Billings effectively made a bowling change at every possible opportunity. Data from the first season of the competition painted a clear picture that bowlers were lined up in the second set of five if they bowled two in a row, and Billings trusted the numbers. Morgan, by contrast, went with his gut and gave Mason Crane two separate sets of 10, and another to Liam Dawson.

Time pressure is a killer: teams have only 65 minutes in which to bowl their balls (albeit with regular top-ups due to reviews or injuries), or else they are forced to bring an extra fielder into the 30-yard ring at the death. On Thursday night, Invincibles missed the cut-off time by eight balls, and Spirit plundered 20 while the extra man was in the ring; Spirit's seven balls with only four out cost 19.

"It definitely feels like you're making more decisions [than in T20]," Billings had explained in the build-up. "You simply don't have the time: it's only one less ball per set, but it does make a huge difference. You have to think on your feet and make decisions really, really quickly." After Invincibles' three-run defeat, he admitted that the whole squad had been "rusty".

For Billings, the challenge is heightened by the fact he is constantly involved behind the stumps. He has spoken to Jos Buttler about the difficulty of being a keeper-captain, and delegated some responsibility to Sam Curran and Jason Roy at mid-on and mid-off rather than constantly sprinting back and forth, but as no-balls and wides piled up, time caught up with Invincibles.

Billings plans extensively before short-form games, and studies something resembling a "cheat sheet" to prepare, which features one key thing to remember about plans to each batter and when to use each bowler. But as Mike Tyson said, everyone has a plan until they get punched in the mouth: Spirit came out swinging with the bat and in the chase, every shot Invincibles' top order played went to hand.

"The rhythm of the game is very different," Billings said. "Let's be honest, we played terribly all day. When you're 12 for 4, normally you're out of the game so to take it down to the last ball is a brilliant effort."

Morgan, meanwhile, is at a different stage of his career and appears to see his role in the Hundred as a vocation as much as a job. "I love playing in games like that. You really get to find out more about your players, the opposition and how good guys are at coping under pressure. It's awesome for English cricket to be able to play under these circumstances."

With the bat, he made his highest score in any cricket over the last year, hitting 47 off 29 balls including three sixes in his first game since his international retirement, but in the field, the game nearly ran away from him. He only used five bowlers, juggling their allocations as carefully as he could, but like Billings, the game slipped out of his control and the cut-off time nearly cost Spirit dearly as Hilton Cartwright, Jordan Cox, Tom Curran and Danny Briggs swung Invincibles back into the contest.

Returning to a format that is only played for a month of the year was a jolt for everyone involved, not least to Nathan Ellis, who won the match award for his 3 for 28 on debut. Ellis had watched highlights of last year's competition but no live games - the time difference means they are tough to follow in Australia - and admitted he was taken aback by the pace of the game.

"I was stumbling my way through it," he said. "You don't really get the chance to talk a lot: even in the timeout, I was sprinting in to get a drink and by the time I got there, I had to get back out. The time constraints made it really tough but as a bowler, having Morgs' calming influence is invaluable."

Off the field, the Hundred is all about the bigger picture: with a crowd of 22,284 gripped until the end by Invincibles' near-miss, the ECB will have breathed a sigh of relief after a false start at the Ageas Bowl on the opening night. But on it, the game has become increasingly detailed and granular for captains: T20 captaincy is tough, but leading a Hundred team is a whole new ball game. --Cricinfo