combinations
Combination choices will depend on what happens during warm up and how many different tread patterns you can afford.
We would usually have same tread pattern front and back, however if course is muddy it may be necessary to adapt. In mud both tubs will be at low pressure for grip. If there is sufficient drive from standard tread rear tub, this will be used as its slightly quicker than a mud tread. The front may be sliding on corners so a mud tub would be preferable if thats the case as it gives greater confidence cornering at speed. However, if there are a lot of cambered sections, the low pressure tub wall may fold over itself at these points on the course. To avoid this a tyre may be used ...green michellin mud prefered..
Not used tyres other than in the case above for a number of years so limited experience.