The shell bone script of character Fight is
Two people are fighting with their hands cross each other.
The small seal script of the character is
The outside curves on two sides are people's body, the inside two 出 are their hands.
The clerical script of the character is
The curved bodies become straight vertical lines, the hands become two 王.
The song typeface for the traditional character is
Almost same as its clerical script.
The song typeface for the simplified character is
Which has 0 similarity to old scripts because it is from making use of character Grain Measure Bucket (Post 373). Making use of or borrow another character to be different meaning is a way to expand the vocabulary in the past. But this time happened in 1950s, the experts of Chinese simplification used the way to combined the two characters 斗，鬥 into one 斗 to eliminate the character 鬥. A way to simplify Chinese characters: let some characters disappeared.
Right now, 鬥 is not a character in simplified Chinese; 斗 has two meanings: Fight and Grain Measure Bucket.