What is meant by 'sandbagging' in F1 testing?

Throughout pre-season testing in Bahrain, one term that will keep cropping up is sandbagging.

At one time or another, all teams engage in the art in a bid to throw rivals off just how fast their car is, but where does the term come from?

In essence, sandbagging in F1 refers to the process of a team, or indeed driver, deliberately posting slower lap-times than the car is capable of to disguise their true potential.

The idea is that you've lulled rivals into a false sense of security and then tip the sand out (metaphorically speaking) ahead of qualifying for the first race when you unleash the everything that your car has actually got.

F1 teams can sandbag by running low engine power settings, using the harder Pirelli tyres or by simply not driving very fast.

Rivals can usually cotton onto what is going on through a variety of methods, including GPS tracing, adjusting fuel loads in their data, and through a racer's gut instinct.

For example, if Red Bull turn up in Bahrain and consistently place 10th on the time sheets, and run the Hard tyres only, it is disguising its true, raw pace.