Yes, Gary, there's been a bug with Message Reply since the New Year.
There is a simple workaround however, that's better than starting new messages.
Please see this post in a good thread on the topic. Above my post there's a pic from ScottHope showing how to do it.
When people start new messages, it just leads to a plethora of threads in one's inbox, making it hard to keep track of what's going on.
It takes just 2 keystrokes (select all/copy all), and 2 more clicks (BacktoMessages / QuickReply button)... to do the longest method... no more than 5-10 seconds depending on browser speed.
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And your first question...
The Worst-Ball series is four-ball. Every player will play their own ball for the whole hole. The worst score for your 2-person team is what will count for that hole, and be compared to the other team's worst score. Whichever is lower wins the hole.