I find the behavior of logger.whatever(format, ....) rather confusing. 1. What bothers me most: Forgetting a brace means that an argument gets ignored, which may mean waiting one more week till something like logger.error("Rare problem: {}, problem, details) fires again. A simple fix would be to follow Guava's implementation like in https://github.com/google/guava/blob/master/guava/src/ com/google/common/base/Preconditions.java#L154 which says "Unmatched arguments will be appended to the formatted message in square braces". This is a simple fix and the behavior gets changed only in case of a user error. I'd gladly contribute the fix. 2. A strange thing is that an exception needs no braces. So logger.info("Foo {} bar {}", o1, o2) leaves {} behind if o2 happens to be an exception. This is no big deal, but it's undocumented. My logfiles are full of braces as it took me a while till I found it out.