Note to self: don't just check. Think!

II must have been drunk on Monday. Drunk on the idea of adding brewer, pub and restaurant chain Greene King to the portfolio.

I was seduced, initially, by an error in Sharelockholmes' record. The database had used the wrong figure, a higher figure, for shareholders' funds/equity/book value (now corrected). That, and the fact Greene King is a local company of national significance. I eat and drink at Greene King establishments. Oh, and my uncle is from Bury St Edmunds, home of Greene King, and the company is as close to his heart as Ipswich Town football club.

But it was the error in Sharelockholmes that led me astray. I have a pre-analysis checklist that is supposed to spot things that might invalidate the figures that attracted me to the share in the first place. It also highlights things I might need to consider when I come to analyse the annual reports. Things like:

• A qualified report from the auditor
• Large defined benefit pension schemes
• Off balance-sheet operating lease commitments
  Significant developments since the last annual report
• Data errors

So I checked the company's price to book value, return on equity, and ratio of equity to assets, the three statistics that led me to think Greene King might be a good prospect, and found them to be rather more pedestrian than reported.

Job done, you might say. Check list completed. Errors found (and reported to Sharelockholmes). Company no longer looks really strong and dirt cheap, it looks kind of average. Time to move on. There may be better opportunities…

You might say that. But for some genuinely unknown reason I ploughed on through a decade of annual reports, adjusting for a bleedin' share split, and completed my spreadsheet for the results going back ten years.

And then I was disappointed, even though I already knew I would be!

I wasn't actually drunk but I had the single minded unquestioning tunnel vision of a drunk. For a guy trying to be more efficient, it's a slightly worrying waste of an afternoon.

Despite my predilection to like Greene King the idea of adding it to the portfolio may have been doomed from the start. I have a general prejudice against pub groups borne out by the near death of over-indebted Enterprise Inns and Punch Taverns. Greene King, is not in their disreputable company but despite investors' experience I think they still see 'well managed' pub chains as safe, high quality investments so there's not much value hidden in the survivors, and perhaps more risk.

Any way, here, for posterity, and people that don't share my prejudices, is Greene King's ten year record. It's not bad, barring the rights issue and the erosion of shareholder wealth in 2009 but the company is just a bit too indebted, and not quite profitable enough for me to add to the portfolio. Its ten year earnings yield is, at 9%, on the cusp of being good value, so maybe one day…