Anyone who has watched F1 for any length of time will know that the overwhelming reason why pole-sitters don't have a better record of race wins is because misfortune can strike any driver: even those with clear track in front of them. Those who backed Mika Häkkinen to win the Spanish Grand Prix in 2001 when clutch failure forced him to retire a mere five corners from victory will be well aware of this.
Given that, no matter how seemingly unassailable his position, misfortune can strike a driver at any time - crashes, mechanical failures, safety cars, race stoppages, time penalties and the like - it is crucial that you arm yourself with as much information as possible. This will allow you to determine when misfortune is more likely to strike, and react to it quickly when it does.
At a very minimum, you need to know the layout of the track. This will allow you to judge, instantaneously, where a collision has occurred, which will help you assess the likely impact it will have on the race. Knowing where the pits are, and where the safety-car line is, will also help you to react to in-play developments.
It's also necessary to have reliable and timely data to hand when betting in-play. Whilst broadcasters generally do a good job of informing viewers of the latest developments in a race, that information will often not be communicated until there is a natural break in race commentary. However, with the official F1 website, and others, offering real-time race data, and a host of weather services showing you the latest metrological patterns at and around a circuit, it is often possible to have access to that information before most other punters, which can make the difference between in-play success and failure.
And when it comes to assessing the likelihood of the driver out-front being able to stay there, you would do well to look at the reliability statistics offered by websites like Viva F1, which also provides a wealth of other information of use to the savvy F1 punter, such as the characteristics of different circuits and the performances of drivers at different tracks.