Consider Murphy, whoever he was. When anything goes wrong, people assume it’s somehow his fault.

Being a forgiving sort of guy, I try to give ol’ Murph the benefit of the doubt. Still, there are some situations in which I am convinced his famous Law, or one its many corollaries, is at work.

Case in point: the tighter the deadline you are facing at any given moment, the longer it takes to get through the grocery store checkout line. If that ain’t Murphy’s Law, nothing is.

As a corollary, the length of time you’re stuck in queue is almost always in inverse proportion to the number of items you’re buying.

I have researched this subject extensively over many decades, and there is no other explanation. It’s Murphy, tossing out one of his universal curve balls.

But take heart. You don’t have to be at the mercy of Mrs. Murphy’s chowder-faced brat. Allow me to suggest some strategies that could save hours of aggravation over the course of a year.

1. Check out who’s checking out. Before you choose a line to join, observe the cashier for a moment. If he/she looks perplexed by the bar code scanner, or pauses in confusion whenever the cash drawer springs open, you’re in for the long haul.

2. Be aware of awareness. If your target cashier doesn’t appear to know rhubarb from rutabaga, or eggplant from aubergine (trick question), move on. But don’t automatically rule out that fresh-faced teen. She may be a major foodie.

3. Go for Grumpy. Friendly is fine, but why stand tapping your toe in annoyance while the cashier chit-chats with every customer about their weekend plans, their adorable pets, or their recent medical dramas?

4. Size isn’t everything. The longest line is not necessarily the slowest. Similarly, bulging carts don’t always take longer to process than those with fewer items.

5. Don’t be too shy to spy. Take a discreet peek at what other shoppers have in their carts. If it’s mostly multiple quantities of standard items, they’ll probably breeze right through.

6. Beware the bulk binners. Even the savviest cashier can have trouble distinguishing Moroccan couscous from South Dakota cream of wheat. Every call for someone to check out an unlabeled bag can stretch your waiting time by an eternity.

7. Honour the organized. Look for shoppers who already have their credit cards in hand before they reach the till, and seem alert enough to remember a four-digit P.I.N. These everyday heroes deserve your respect and gratitude.

Let’s do this, folks. Let’s tell the anonymous Mr. Murphy that his Law is not immutable, and we don’t have to obey.