Let's talk about the beautiful jacket cover of Wilberforce, designed by Jonathan Lippencott and his brilliant team at FSG. The painting here is period, and so the clothing is accurate to the novel: cricket flannels, shirt, school tie around waist. But what is he holding in his hand? This took some deep googling, but turns out this is an open-palm batting glove.
You wear it over the back of your hand, fingertips through slots on the reverse side. The strap wraps around your wrist, and the nubby bit goes over your thumb. The point is to let you feel the bat while protecting your hand from getting thwacked by the cork.
Here are Hobbs and Sutcliffe wearing a lighter, spikey version that shows the wraparound:
I think this photograph is from the Ashes, 1926.