Here is a good description of General Bragg...
"Moreover, he was not healthy enough to command in the field. He couldn't withstand the months of campaigning necessary. Throughout the war, he suffered from rheumatism, dyspepsia, extreme nervousness, and severe migraine headaches. His persistent poor health helped make his temper sour and petulant. Often, he was too sick to command. In the spring of 1863, for example a siege of boils disabled him. At that time, General William J. Hardee said Bragg was too feeble "either to examine and determine his line of battle or to take command on the field." And English Colonel James Freemantle, who was visiting the Army of Tennessee then, wrote in his diary, "He (Bragg) is very thin. He stoops, and he has a sickly, cadaverous, haggard appearance. . ." "During periods of illness and mental depression, Bragg is as much influenced by his enemies as by his friends," said General W.W. Mackall, "and he does not know how to control the one or preserve the other. Sometimes he is blind as a bat to the circumstances surrounding him." Mackall's view was echoed by Dr. J.C. Knott, who told Bragg, "Your best friends admit that your temper is irascible and that, under excitement, you sometimes say harsh things when there is no necessity for it, and sometimes even wound an innocent man."
What I am suggesting is that Bragg's personality prevented him from being more than a mediocre field general. He lacked tactical flexibility. He became unduly excited during battle, and either made hasty decisions or stuck too rigidly to predetermined plans. He was too impatient. He was unable to wait out his opponent. In nearly all of his battles, he was the attacker. He seldom let his army entrench. "General Bragg says heavy entrenchments demoralize our troops," reported President Davis' military aide. Bragg was always too engrossed in the details of moving, disciplining, organizing, and feeding his men to master the broader and more comprehensive duties of a battle leader. Personally, he was courageous. No question about that, but he lacked that quality all great commanders need: the mental strength and will to dominate whatever event or crisis occurs on the battlefield. At Perryville and at Murfreesboro, Bragg lost his nerve. He changed under the strain of combat from a bold aggressor to a cautious retreater."
Braxton Bragg: Misplaced General
by Dr. Grady McWhiney