# Are there any signatures where the recid (v) is equal to 29,30 (or 33,34 compressed)?

Peter Wuille recently explained how ECDSA pubkey recovery is done, in response to my question.

So it's basically that for a given base64 signature, the value `v` in `v,r,s` provides the specific coordinates, hence the `recid` (recovery ID).

Example from BitcoinCore test vectors:

``````> sig =
> "H8PgOb/liZzt3QQHJn9kLBqH7E/i+SC6JTwYGtdNdOjnXzFqXnHMZqP7oZ1wb1QiQ3H/kF8xC9Yx7pK9ddlx8TA"
> addr = "1K5Z1nxN4mjUgCLpSXMRkeZxuAMpbn2CQB" wif =
> "KwfJTiKdcjNMjBu4ksgGd21EZXz6JomoZNbirP3nfd3K9ZMXMEUi"
>
> v,r,s = vrs = (31,
> 88597177789312009809148107221292570613390338668815747761545214128303675599079L,
> 43057030252916568867525408201971649068117337291455262356277580652864892694832L)
``````

The value of v is `27 + recid` for uncompressed keys and `31 + recid` for compressed keys.

Ive run a Python loop using pybitcointools which signs a message using a random key, and I've yet to ever see `v=29` or `v=30`. Why is this? Is it by design, or is it just a very low probability event?