The ongoing Test between Zimbabwe and Bangladesh could be considered as a contest for No 9 in the Test rankings, but has had moments of statistical interest. First there was a 191-run stand for the 9th wicket which is the second highest in all Tests. Now there was another weird score by Zimbabwe’s debutant opener Takudzwanashe Kaitano . We may need to remember his first name in the years to come.
He started off with 87 off 311 balls, which had a scoring rate of 27.97.
In the second innings he opened again, with Zimbabwe needing to make 477 in over 4 sessions. This time he scored 7 off 102 balls, and was out at 132/3.
What are the slowest scoring rates for innings over 100 balls?

Kaitano’s 6.86 is the third slowest here, with only JT Murray and today’s N Wagner ahead of him. India’s Yashpal Sharma did a little better with a scoring rate of 8.28.
Let us also look at the real batting marathons for innings over 500 balls:

These are all the scores above 500 balls where the number of balls were recorded. They were not recorded in some triple centuries such as Sobers’s 365*, Hanif’s 337 and Hammond’s 336*. It would be particularly interesting to see Hanif’s scoring rate.
Chanderpaul, Hammond and the lesser known Radley have the first three places here. Pujara has the slowest for India.
Finally, we look at the slowest scoring rates for careers exceeding 1000 balls faced. Again, full data is missing for many of them.

The slowest undisputed career scoring rates are for tailenders Morrison, Hoggard and JK Lever.
NS Yadav has the lowest (estimated) rate for India. His batting did help in saving at least a couple of Tests.
Jardine has the slowest scoring rate for frontline batsmen, unless you want to include TE Bailey in this category.