Unless I'm losing my mind, in list view I used to be able to highlight the clip, then press space bar to play. Now, in 10.2.2 I highlight a clip and press spacebar. Nothing happens. I have to actually click in the filmstrip area above the list or press L instead.
Such a shame to see a perfectly good mind go to waste. ;P
Dunno, it's working.... sort of... here. Can't say I've a yardstick by which to judge, as I rarely did exactly what you're saying. But when I select a clip, hit spacebar, it plays.... after an almost :02 delay! Sad. However, if I scrub/mouse over the clip & hit spacebar, it plays instantly. Happy. (This is my usual method in List view.)
In thumbnail mode, using the next edit command, which in the Browser jumps to the beginning of the next clip, and hit spacebar, the clip plays instantly. Huh. Seems like this should be the same "performance functionality" as List view. That is, there's not a preceding "scrub" to buffer video for RT playback.