Sore Bears, and bros that are foes
Also: Has anyone scored a fifty in a team score of under 100 in a Test?

Sialkot Stallions won 25 T20 games in a row between 2006 and 2010 • AFP
There have been three instances of a batsman making an individual half-century in a completed team innings of less than 100. The most recent example was also the most extreme: when Sri Lanka were bowled out for 82 by India in Chandigarh in 1990-91, Asanka Gurusinha scored 52 not out, or 63.4% of the total (this remains the sixth-highest percentage by a batsman in any completed Test innings). The previous instance was also by a Sri Lankan: Arjuna Ranatunga scored 51 out of 97 (52.5%) against New Zealand in Kandy in 1983-84. And back in 1957-58, Trevor Goddard carried his bat for 56 out of South Africa's 99 (56.5%) as they slumped to an innings defeat by Australia in Cape Town.
You're right that Sialkot Stallions have the longest winning run in T20 matches - 25 in a row, between February 2006 and October 2010. Next come the New Zealand province Otago and the Kolkata Knight Riders with 14, then Surrey with 13 in 2003 and 2004, in the early days of T20. Otago actually went 15 games without defeat, as their run of victories was ended by a tie (although they won the one-over eliminator), against the South African Lions in Jaipur in the Champions League T20 in September 2013.

Roelof van der Merwe's astonishing innings against Surrey in Taunton last month - he came in at 22 for 5 and slammed 165 not out - is actually the second-highest by a No. 7 batsman in all List A (senior one-day) cricket, behind only Luke Ronchi's 170 not out for New Zealand against Sri Lanka in Dunedin in 2014-15. Van der Merwe's innings was the highest by a No. 7 in England, beating Sam Billings' 135 not out from 58 balls for Kent against Somerset - also in Taunton - in 2014.
There are actually two instances of this. The recent one involved the fast-bowling Pattinson brothers: Darren was a rather controversial choice in one Test for England, against South Africa at Headingley in 2008, while his brother James Pattinson has so far played 17 Tests and 19 white-ball internationals for Australia. Darren was born in Grimsby, in England, but James was born in Melbourne. Interestingly, James has now followed Darren to Trent Bridge, where he has been playing for Nottinghamshire.

Don Bradman did hold the record for runs in the Sheffield Shield - Australia's domestic first-class competition - for many years: he made 8926, at an average of 110.19, in only 62 matches, with 36 hundreds. But a lot more matches are played now - Western Australia and Tasmania did not take part in the Shield in the Don's heyday - and Bradman has been pushed down to 17th on the current list, although he was still on top until the early 1980s, when John Inverarity crept past his tally, finishing his long career with 9341 from 159 games, at an average of 38.44. In first place now is Darren Lehmann - Australia's current coach - who amassed 13,635 runs in the Sheffield Shield. He's nearly 3000 clear at the top, although there are six other batsmen with more than 10,000 runs: Jamie Cox (10,821), Jamie Siddons (10,643), Michael Bevan (10,621), Brad Hodge (10,474), Matthew Elliott (10,263) and Martin Love (10,132).
Steven Lynch is the editor of the updated edition of Wisden on the Ashes