In every game there are times when the difference between two possible moves is very small and one shouldn't expend too much mental energy on choosing the best play. The converse is equally true and there are some rolls where selecting the best play is absolutely critical and you should invest both time and energy in getting it right.
Such is this week's play where black has to choose between (a) 21/12* and (b) 8/2*, 5/2. These moves are radically different in approach and one of them is likely to be considerably better than the other - but which one?
(a) escapes a back man and sends another white man back behind black's nascent prime. On the down side black has three blots at a time when white's board is as strong as his own and a return hit could prove dangerous. (b) makes a four-point board with a man on the bar but does nothing about the back men. Equally well it has few immediate risks.
(a) is superficially attractive because it seems to achieve so much with one roll but (b) is actually the much stronger play. The basic plan when playing against one man back is to attack that man. Here black can do so at no risk while at the same time improving his board. Depending upon white's roll he can continue the attack next time or, if white stays on the bar, use the opportunity to escape his back men.
In the game black played 21/12* and got his comeuppance after white entered with 11 - bar/23, 6/4* - and then black fanned with 62. White won with a redouble shortly thereafter.