Graeme Swann answered most emphatically today as England sought to prove their Test match well-being in an inevitable draw at Buffalo Park.
Swann arguably had least to prove among a trio of bowlers in obvious contention for next week's opening Test against South Africa.
But halfway through his match-time preparation for Centurion, the off-spinner could reflect on figures of six for 55 - including three wickets in four balls - as the South African Invitational XI batsmen faltered in this first of two back-to-back fixtures.
Among Swann's team-mates, seamers Graham Onions and Stuart Broad had mixed fortunes - the latter wicketless and warming to his task only slowly.
With uncertainty still surrounding James Anderson's recovery from a mystery knee injury - the Lancastrian and fit-again Ryan Sidebottom are both expected to play tomorrow - England need to be clear on their other options.
As the hosts closed on 167 for seven in reply to 329 for six declared, it was Swann - bowling for the first time since England's one-day international defeat in Cape Town almost two weeks ago - who impressed most, and bagged by far the best statistics.
Alastair Cook's 81 and a stand of 83 between Ian Bell and Matt Prior on a slow surface provided evidence that England's batting is in pleasing shape too.
With the ball, Onions was first to strike - after England had given themselves just over an hour in the field before tea.
Opener Andrea Agathagelou went lbw, across his stumps one time too many and missing some swing in the Durham seamer's third over.
Divan van Wyk appeared increasingly comfortable, in company with number three Sammy-Joe Avontuur (68), until he too fell lbw - playing across Swann's second delivery.
Swann doubled up soon after tea when Temba Bavuma propped a catch to short-leg - and he added his third wicket, collecting a return catch from Piet van Niekerk's mishit.
Avontuur, however, was making England work a little.
He reached a 65-ball 50 with his eighth four, a cover-drive off the returning Onions, but went into his shell as England used the final hour to give Swann and Broad more practice.
The bonus came for Swann with three wickets in an over, Avontuur's the first when he charged down the pitch and missed - with the next two batsmen guilty of recklessness before they had scored.
England had begun the day by losing two wickets in the first hour of a squelchy morning.
Groundstaff performed wonders to get play under way on time, after heavy rain yesterday, and the teams had to compromise plenty too to take the field with swathes of sawdust needed to soak up mud around the square.
England resumed on 142 for three. But with overnight pair Paul Collingwood and Cook soon gone, Bell and Prior took their chances for time at the crease before the start of the four-Test series.
Collingwood went in the first full over of the day when he chipped a straightforward catch to short midwicket off Siya Ntshona.
His dismissal was entirely typical of a slow pitch which has spent so much of the past week under cover - and so too was Cook's half-an-hour later.
The opener almost had a hundred in his sights when he failed to stay on top of a push drive and was well caught at mid-on by tumbling home captain Wendell Bossinger to give Charl Pietersen his third wicket.
Bell and Prior quickly achieved a fluency which had proved beyond some, taking advantage of vulnerable back-up bowling - as did Swann after the sixth-wicket pair had both retired out at lunch.
Meanwhile, the latest indications from the South Africa camp are that injured all-rounder Jacques Kallis may yet be fit to bowl in the first Test.
Kallis has spent time in an oxygen chamber to aid his recovery from a broken rib - and although he is still rated only 50-50 to bowl as well as bat at Centurion, South Africa are confident he will be able to do both from the second Test onwards.