After Joe Root wandered back in at Lord’s two Saturdays ago on 180 not out, the Wisden Cricket Monthly editor, Phil Walker, described him as “strumming” his second century of the series. When Root went to three in a row at Headingley the next Friday, he was absolutely strumming them. England’s captain has never looked as relaxed; all smiles and easy drives, no need to launch at the bowling, just serenely nodding it away, closing his eyes here and there for an especially enjoyable chord.