How a damaged club and a damaged golf ball are treated under the 2019 Rules of Golf has changed significantly.
In the past, a player could use a damaged club only if it was damaged in the “normal course of play”. If a club was damaged in anger, that club could not be used again during the round, as its use resulted in a DQ.
For 2019, a player may keep using any damaged club no matter how the damage was caused, even if the player smashes the club in a tizzy.
This simplifies the rule and helps a player avoid a DQ for not realizing some damage occurred.
But really, it would be better to just hold your temper.
Also for 2019, the definition has changed for a damaged golf ball that may be replaced during the play of a hole. Now, it must be clearly seen that your original ball is “cut or cracked” — not merely scratched or scraped or with its paint damaged or discolored.
So no more taking a ball out of play because it has a “cart path logo” on it…