When you go shopping for a car, you will find a dizzying array of choices in the market. There are sports cars, trucks, sedans, convertibles, SUVs, vans, hybrids, luxury, economy, large and small cars. I think many people purchase automobiles according to their needs but if you're in a mid-life crisis, you might go nuts and buy a shiny new red Corvette or a Porsche. Fact is, we buy cars according to our stages in life, how much we can afford and how many kids we might need to shuttle around.
A martial art system is like an automobile in that there are numerous choices for every type of person. People under 300 pounds should probably not opt for Sumo, let's say. If you have bad knees and a creaky back, a dynamic kicking art like taekwondo may not be your spot of tea. If you are stocky and have a low center of gravity, judo might be your thing. Some may like the zen-like qualities of a art like Iaido (a form of Japanese swordplay) or Kyudo (a form of Japanese archery). One who has a small stature may want to consider aikido which leverages an opponents force against them.
Many arts would claim superiority over another and many duels and challenges have taken place as a result over the years. Miyamoto Musashi went around the country seeking sword masters to challenge them to duels, most often resulting in death. You can say that this is definitive proof of one's skill but it's not practical in today's society.
Take an honest inventory of your attributes, physically, mentally and spiritually prior to selecting an art. Carefully research the characteristics of different martial arts and try to match them with your goals and best fit. Many studios will offer you a complimentary trial class or two so you can honestly evaluate them by trying it out. Although it is often disrespectful to some old school masters to ask questions about the art, if you are going to make a financial and time investment to an art, you should be afforded a good answer. Be comfortable with the instructor you are going to choose because they will be a large part of your success factor. I'll talk to this subject in another article.