Good question! Some metrics make sense to be broken down into left and right values (for example, contact time) and other do not (pace or step rate). Contact time can vary between your left and right and the variance supplies value -- potentially indicating some type of asymmetry. The same is not true for pace, step rate or stride length. For these, what we've done is combine the data from the left and right scribes, accounting for areas of discrepancy. This gives us the 'truest' answer for these metrics. This means that the value is no longer graphed on a step to step basis, but rather, each point represents the 'average' for a period of time. As a result of some feedback we've been getting on the recent changes, we've been looking at introducing a 'step length' metric. Some users had been utilizing differences in 'stride length' as an indicator of asymmetry. Having different stride lengths doesn't necessarily make sense, but different step lengths could be very informative. I'm sorry that the json structure change is causing you difficulties. Making such changes is something we'll need to do every once is a while as the system grows. At some point we hope to build out a public API where such changes are more controlled, ensuring for backward compatibility and versioning.