how do i no if my bullmastiff puppy has a good pedigree ? in a bullmastiff what is the best pedigree/bloodlines?

A good pedigree would be one where the ancestors were all specimins that closely met the standard.  You would expect a reasonably high proportion of dogs that are champions (say around a third or more of a 5 generation pedigree) and others to ahve Stud Book numbers etc.

A poor pedigree would be one with dogs who were poor examples of the breed.  so knowing a good or bad pedigree would mean you would need to know the dogs in it, though you would expect the Champions to be a sign of quality.

Of course Two Champions can still produce poor offspring, but non champions are less likely to produce champions if the dogs behind them are poor.