What's the highest percentage of runs conceded by one bowler in an innings in a T20I? Tymal Mills went for 45 of Australia's 125 the other day… asked Brian Richardson from Australia
Tymal Mills conceded 36% of Australia's runs in their total of 125 in England's T20 World Cup match in Dubai the other day. That's actually a fair way down the list, looking only at innings in which a side was bowled out, or lasted at least 18 overs.

On top is the Czech Republic's Honey Gori, who leaked 61.9% of Turkey's runs in Ilfov County in August 2019 - he only conceded 13, but Turkey were skittled for just 21. Next comes the leader among Test-playing nations: when Australia made 105 for 7 to beat Bangladesh in Mirpur in August, Shakib Al Hasan conceded 50 of the runs (47.62%). Next among the bigger nations comes Angelo Mathews' 43.33% - 26 out of 60 all out - for Sri Lanka against New Zealand in the T20 World Cup in Chittagong (now Chattogram) early in 2014.

There's one higher percentage in women's T20Is. When Nepal bowled Maldives out for 8 in Pokhara in December 2019, six of the runs - all of them wides - came from the opening over, bowled by Kabita Kunwar. That's 75% of the eventual total. Maldives were 6 for 0 after that first over, then managed only two more runs (including the only run of the innings off the bat) in the next 10.3 overs.

Jos Buttler now has a century in all three international formats - how many players have done this? asked Divyanand Valsan from India
That excellent hundred, completed off the last ball of the innings against Sri Lanka in Sharjah last week, made Jos Buttler the 18th man - but the first from England - to have scored centuries in Tests, ODIs and T20Is. The others are Glenn Maxwell, David Warner and Shane Watson (Australia), KL Rahul, Suresh Raina and Rohit Sharma (India), Brendon McCullum and Martin Guptill (New Zealand), Tillakaratne Dilshan and Mahela Jayawardene (Sri Lanka), Tamim Iqbal (Bangladesh), Ahmed Shehzad, Babar Azam and Mohammad Rizwan* (Pakistan), Faf du Plessis (South Africa), Chris Gayle (West Indies) and Kevin O'Brien of Ireland.

England's Heather Knight is the only woman to have a complete set, although Mithali Raj of India just missed out - she scored centuries in Tests and ODIs, and has a best score of 97 not out in T20Is.

Is it true that Alan Igglesden, who sadly died last week, was told he was the 15th choice when he turned up to make his Test debut? asked Harry Ward from England
The sad news of the death of the Kent and England fast bowler Alan Igglesden last week, at the early age of 57, did bring to mind the slightly chaotic circumstances of his Test debut, for the final Test against Australia at The Oval in 1989. Beset by injuries and defections to a rebel tour of South Africa, England used 29 players in that series including, for the sixth Test, two debutants in Igglesden (even though the captain David Gower had never seen him bowl) and the Essex batter John Stephenson.

Micky Stewart was the England manager/coach at the time, and the situation was explained in his 2012 autobiography, written with Stephen Chalke. "Before the press conference, Micky undertook a calculation. Of the first-choice opening bowlers around the 17 first-class counties, nine were overseas players, five had been banned for signing up for the rebel tour, and a further seven or eight were out of action with injuries. He explained all this to the assembled journalists, not meaning to suggest that Igglesden was lower in the pecking order than every one of those who were unavailable. Nevertheless his explanation led Jim Swanton in the Daily Telegraph to comment that it could not have done Igglesden's confidence much good to know he was there as the 15th choice."

Igglesden's three wickets at The Oval were distinguished ones: Mark Taylor and Steve Waugh in the first innings, and Geoff Marsh in the second. Stephenson would remain a one-cap wonder - and helped found an informal club for such players - but Igglesden did play two more Tests, in the West Indies in 1993-94.

Who is the oldest player to debut in Test cricket - and who's currently the oldest player still playing? asked Dilruwan Jayarathne from Sri Lanka
We have to go back to the very first Test match of all to find the oldest debutant - England's James Southerton was 49 when he played against Australia in Melbourne in 1876-77. Second on the list - and the oldest since the Second World War - was the offspinner Miran Bakhsh, who was almost 48 when he appeared for Pakistan against India in Lahore in 1954-55. The oldest this century was Ed Joyce, who was 39 when he made his only Test appearance for Ireland, against Pakistan in Malahide in May 2018.

As for current players, and barring yet another comeback for 42-year-old Chris Gayle, the oldest man who appeared in a Test in 2021 is Jimmy Anderson, who has played four matches now since turning 39. Gayle was the oldest man to feature in the ongoing T20 World Cup, ahead of two 41-year-olds in Mohammad Hafeez and Ryan ten Doeschate.

Which umpire has stood in most India vs Pakistan matches? asked Aditya Agarwal from India
A batch of third-country umpires lead the way here. Simon Taufel oversaw 21 India-Pakistan matches (seven Tests, 12 one-day internationals and two T20Is), while Rudi Koertzen did 20 - but Koertzen had an additional three as the TV umpire. David Shepherd stood in 19, Steve Bucknor 14, and Billy Bowden 11. Then come the Pakistanis Asad Rauf and Khizer Hayat, with ten apiece. Ian Gould also umpired in ten India-Pakistan games.

Thanks to Shiva Jayaraman of ESPNcricinfo's stats team for his input on some of this week's questions.

Nov 9, 2021, 8.43 GMT: Babar Azam and Mohammad Rizwan were added to the list of batters who have scored international hundreds in all three formats

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Steven Lynch is the editor of the updated edition of Wisden on the Ashes