ECDSA signatures have in theory the same probability of being low-S as being high-S. The Bitcoin Core v0.9.0 release in March 2014 included a malleability breaker for the Bitcoin Core Wallet. This malleability breaker made sure that all signatures generated by the Bitcoin Core wallet are low-S. As the malleability problem got bigger other wallets started producing low-S-only-signatures as well.

With the release of Bitcoin Core v0.10.3 and Bitcoin Core v0.11.1 in October 2015 high-s signatures were made non-standard to removed the transaction malleability vector.

Related Charts

r and S-values in Bitcoin ECDSA Signatures

Shows the distribution of low and high r and S-values in ECDSA signatures per day.

DER encoded ECDSA Signatures

Shows the distribution of DER-encoded ECDSA signatures per day.

Length of ECDSA Signatures

Shows distribution of ECDSA signature length per day.

Signature Count per day

Shows the number of ECDSA and Schnorr signatures per day.