First thing to know when showing a mastiff is your going to run into more politics you ever thought possible.
By politics I'm talking about showing against dogs that the owners have paid a well known "pro" handler to show their's. When I say well known handle I'm referring to a handle who knows lots of judges personally and the judge knows them. Don't ever think the best dog always gets the win, far from it!
Lots of times dogs get advertised in magazines that judges look through. The advertising is quite expensive, but people (mostly breeders) will pay anything to see their dog win. As much as $100,000 a year to the handler alone.
Their will be many times you pull up at a show where your beat before you step out on the ground and it will have nothing to do with who has the best dog.
I speak of this from experience. From watching a judge walk past dogs with out really looking at them to get to that dog with the handler at the other end of the lead they just got through talking with and joking around with before the show started, more times then I like to remember.
There are some judges that don't play that game, but not nearly enough of them. If you show you will see it and learn. My wife and I showed one called Harley. She quickly learned how to handle in a ring, then showed him from show to show as a special. Our goal was to get him ranked and an invite to the eukanuba held in Orlando, Fl. That was in 2002. Well we hit the trail from show to show trying to get enough win breed points to get that done at the end of the year.
We saw more political wins by lesser dogs to the point of getting sick at times. The good news was we still got him ranked 13th in the country and got the invite we set out to get. We beat the number 0ne dog in the country along with several rank ones along the way. Talk about Mad owners of those dogs WOW! Nothing but nasty comments from most of them, even though Sue always gave them a congrats them when they got their political wins!
When you get lucky enough to find a judge who judges dogs only and take that win, there's no better feeling to know your dog won on his merits alone, nothing else. Feelings that not many who pay for wins ever experience.
So if you decide to show, go into it knowing you will get beat from politics on a regular bases, depending on what shows you attend. Also remember even their money can't beat you every time if you have the better dog! Those shows you beat them at will make it all worth while. Not to mention meeting the mastiff folks there just like you who become good friends and you have a lot of fun with at those shows.
Good luck when you hit the show ring. Don't take the silly losses hard, just know what they were. When you beat the odds there's no better feeling on the trip home!