Extraordinary post from Eugene Wei. Ostensibly it's about how to make better graphs, but it's surely the most compelling, beautifully written post about Excel charts ever written.

“Even with that process, much could go wrong. While I tried to create guardrails to preserve formulas linking all the workbooks, everything from locked cells to bold and colorful formatting to indicate editable cells, no spreadsheet survives engagement with a casual user. Someone might insert a column here or a row there, or delete a formula by mistake. One month, a user might rename a sheet, or decide to add a summary column by quarter where none had existed before. Suddenly a slew of #ERROR’s show up in cells all over the place, or if you’re unlucky, the figures remain, but they’re wrong and you don’t realize it.

Thus some part of every month was going through each spreadsheet and fixing all the links and pointers, reconnecting charts that were searching for a table that was no longer there, or more insidiously, that were pointing to the wrong area of the right table.

Even after all that was done, though, sometimes the cells would not calculate correctly. This should have been deterministic. That’s the whole idea of a spreadsheet, that the only error should be user error. A cell in my master workbook would point at a cell in another workbook. They should match in value. Yet, when I opened both workbooks up, one would display 1,345 while the other would display 1,298. The button to force a recalculation of every cell was F9. I’d press it repeatedly. Sometimes that would do it. Sometimes it wouldn’t. Sometimes I’d try Ctrl - Alt - Shift - F9. Sometimes I’d pray.

One of the only times I cried at work was late one night, a short time after my mom had passed away from cancer, my left leg in a cast from an ACL/MCL rupture, when I could not understand why my workbooks weren’t checking out, and I lost the will, for a moment, to wrestle it and the universe into submission. This wasn’t a circular reference, which I knew could be fixed once I pursued it to the ends of the earth, or at least the bounds of the workbook. No, this inherent fragility in linked workbooks in Excel 97 was a random flaw in a godless program, and I felt I was likely the person in the entire universe most fated to suffer its arbitrary punishment.

I wanted to leave the office, but I was too tired to go far on my crutches. No one was around the that section of the office at at that hour. I turned off the computer, turned out the lights, put my head down on my desk for a while until the moment passed. Then I booted the PC back up, opened the two workbooks, and looked at the two cells in question. They still differed. I pressed F9. They matched. ”

Sorry about the huge quote but it's seriously all so good.

The actual point of the post - how to make graphs better - is pretty much summed up by the title. The quickest, easiest way to make your line graphs easier to read is to delete the legend. Instead, label the data series directly on the chart. Easy, huh?