Or, in English, the time you spend on an issue in tribunal should be proportional to the importance of the issue and its complexity.
The amount of time you spend on something will send a message to the tribunal. The more time you spend on a point the more important you suggest that it is.
So, all else being equal, you should spend the most time on your important points.
However, all else is not equal and you will have to take account of how complex your points are. A difficult issue takes more time to deal with. And if what you have to say is short and simple it does no good (and normally does harm) to keep talking once you’ve made the point.
It is sometimes worth flagging up exceptions to the general rule. For example you might say “Sir, my next point is really the key to this case, but it’s a simple point and I will be brief.” Similarly, you might say “Madam, the contractual point is rather difficult and I’m afraid I’m going to have to spend rather a lot of time on it.”
Update: A reader points out that, arguably, the equation should be importance multiplied by difficulty; rather than importance divided by difficulty. This is correct – unless difficulty is expressed as a number greater than zero but equal or less than 1. This may be a post event rationalisation, but it preserves the original formula.