where did the shape of a rugby ball come from
Rugby ball Until 1870, rugby was played with a near spherical ball with an inner-tube made of a pig's bladder. In 1870 Richard Lindon introduced rubber inner-tubes and because of the pliability of rubber the shape gradually changed from a sphere to an egg. In 1892 the RFU endorsed ovalness as the compulsory shape. The gradual flattening of the ball continued over the years.[2] The introduction of synthetic footballs over the traditional leather balls, in both rugby codes, was originally governed by weather conditions. If the playing surface was wet, the synthetic ball was used, as it didn't absorb water and become heavy. Eventually, the leather balls were phased out completely.
Conversion (gridiron football) The try/convert is among the oldest parts of the game of gridiron football and dates to its rugby roots. In its earliest days, scoring a touchdown was not the primary objective but a means of getting a free kick at the goal (hence why the name "try", more commonly associated with rugby today, is still used in American football rule books), and thus early scoring rubrics for the game gave more points to the subsequent kick than the actual advancement of the ball over the goal line. The related term "conversion" is still used in both rugby union and rugby league to refer to extra points scored by kicking the ball through the posts after a try has been scored.