Sentence ending かどうか


I'm familiar with the usage of かどうか for "whether or not," but I can't
understand its usage in the following example:

> 部の記録見る限り７０符なんて千局に一回出るかどうか

Is this an idiomatic usage of it? Since I'm pretty sure its supposed to
indicate that the probability is even less than 1/1000 games.




だ or です is omitted after this かどうか. The more canonical version of this
sentence is like this:

> 部の記録 **を** 見る限り７０符なんて千局に一回出るかどうか **だ** 。

This sentence means "the probability is 1/1000 or even less" rather than "the
probability is even less than 1/1000". You can think of this `Aかどうかだ` pattern
as "A, or even worse" or "may or may not A".

See this question for more examples: [Understanding
～かどうかだ](https://japanese.stackexchange.com/q/53920/5010)




だ or です is omitted after this かどうか. The more canonical version of this
sentence is like this:

> 部の記録 **を** 見る限り７０符なんて千局に一回出るかどうか **だ** 。

This sentence means "the probability is 1/1000 or even less" rather than "the
probability is even less than 1/1000". You can think of this `Aかどうかだ` pattern
as "A, or even worse" or "may or may not A".

See this question for more examples: [Understanding
～かどうかだ](https://japanese.stackexchange.com/q/53920/5010)

