BitPay introduced one potential fork of Bitcoin Core in a series of blog posts by CEO Stephen Pair. In the series, Pair describes an “adaptive block-size limit.”

Pair expressed his belief on the Medium post’s that he believes Bitcoin does not need a fixed limit, though that would create uncertainty for miners.

Pair believes there can be a “hard limit” – the maximum block size – and a “soft limit,” which miners could increase or decrease if they want. The soft limit will be the default limit for miners to create blocks. As Pair lays out in the fourth and final essay in a series:

At BitPay, we will experiment with this approach. We will perform back testing to analyze what impact various settings might have on historic blocks. We will also analyze behavior under extreme circumstances and critique it from a game theoretic perspective.

BitPay, busy on GitHub, recently opened a “work in progress” pull request, however closed it shortly thereafter. A BitPay developer explained the company likes to do things in an open nature. You can see them working on a “Block Size Calculator.” In other pull requests, it appears BitPay developers are using BIP9. BitPay also created a gitian repo, a way of verifying software over the Debian open-source operating system. In fact, the BitPay proposal appeared on the roadmap of another Bitcoin client proposal, Bitcoin Classic:

Variation on Stephen Pair/BitPay’s idea for a new consensus rule: validation cost (CPU+bandwidth+UTXO storage) for blocks in current 2016-block-difficulty adjustment period must be less than a small multiple of the average validation cost of the last difficulty adjustment period.

Pair was on the losing side of one of the largest thefts in Bitcoin history, when a hacker gained access to a BitPay C-level executive’s e-mail, and tricked Pair into sending the hacker $1.8 million in three payments. The firm shortly thereafter laid off employees.

BitPay has been one of the quintessential Bitcoin companies, processing transactions for thousands of merchants, and playing a large part in simplifying Bitcoin for industry, thus leading to much of the adoption of the nascent digital currency.