Why do my truck start 9 times out of ten

What are you doing when you push start it that you do not do when you use the starter to start it. I will guess that you put your foot on the gas pedal? All vehicles require scheduled maintenance and tune ups and cleaning on a regular basis. It looks like you need to clean your throttle body. When was your last tune up and what do you change on a tune up, some folks do minimum items while other do a real tune up. Of course you could have an electrical problem or an intermittent sensor but you would need to test for those problems when the engine does not start and you need a scanner for that.