A response from Vitalik with actual numbers <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;ethereum&#x2F;comments&#x2F;38jiyv&#x2F;are_ethereums_block_times_better_than_bitcoins&#x2F;crvzkch" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;ethereum&#x2F;comments&#x2F;38jiyv&#x2F;are_ethere...</a><p>&gt; Okay, fine, under normal conditions bitcoin blocks are 98% likely to be final but ethereum blocks are 80% likely to be final. However, six bitcoin blocks provide a one minus one in a billion finality guarantee (since 0.02 <i></i> 6 &lt; 10-9) and 13 ethereum blocks provide that same guarantee (0.2 <i></i> 13 &lt; 10-9), so it&#x27;s still the case that what bitcoin provides in 60 minutes, ethereum provides in 156 seconds. Sure, not in six blocks, but it&#x27;s a battle of linear versus exponential, so the more fine-grained you can make the single-block confirmation time the better.<p>There are also uncle rewards which mitigate the miner incentives.<p>I see benefits to both systems and longer block times are clearly more efficient, but since Ethereum is an application platform a 10 minute block time is untenable. It may be less efficient, but I don&#x27;t think thats a nail in the coffin.