Ebay has changed their search algorithm to match other website which are using a LIKE operator. So this means it appears that search results are showing irrelevant things, but whatever you typed in is being appended with similar terms that you didn't type in. Ebay fortunately does still support multiple NOT operators and thus a query such as this is useful
baseball box -break -bottom -empty -flattened -panel -blaster -pick
But it depends on the website as to whether it supports multiple NOT operators, for example DDG does not recognize more than one.
FWIW this is part of a long running trend in technology where a developer decides that they no longer require the user to be relied on being able to be competant enough to use the software properly. AKA: dumbing down the system to a degree that it causes competant users problems.
PS: Ebay also supports quotes, so you can use a query such as
"Complete Set"
which should exclude 'complete your set' results.
TCDB Collection Leaderboard spots:
#1 Alexei Zhamnov #1 Shane Doan #1 Phoenix Coyotes #1 Arizona Coyotes