Misleading Numbers

Thoughtful anglers analyze data in the attempt to make better decisions about where, when and how to target fish. The most successful ones realize how bigger data samples lead to more useful conclusions and how percentages better illuminate trends, when compared to raw numbers. Drawing broad conclusions from small sets of data can lead to false assumptions. Basing decisions on raw numbers rather than percentages can do the same. Relating my own personal experiences in specific ways clarifies the two previous statements.

My priorities as an angler evolved to a point where I developed singular focus on catching speckled trout of magnum size on artificial lures. Over time, I've kept track of the big trout I, my friends, partners and customers have caught. I don't keep detailed records related to trout measuring between 20 and 25 inches, but I do have data recording the catching of bigger ones. I can make a fairly accurate estimate of the number of fish we've caught which measured between 25 and 27 inches, but my numbers documenting trout meeting or exceeding 27 inches are more accurate. Increasing the length number increases the accuracy of the data; my records related to fish measuring at least 29, 30 and 31 inches are basically spot on.

For an angler, simply knowing how many fish of a particular size one has caught or been part of catching isn't particularly useful in terms of making decisions about where to fish. In order to use of the numbers meaningfully, one must also know the locations where people caught the fish, then convert the raw numbers into percentages by considering how many visits to the locations resulted in the production of the raw numbers. My data about locations falls apart somewhat in terms of specificity when we draw the line as low as 27 inches.

If we draw the line at 31 inches and/or ten pounds, the data becomes more useful in one way, because it's 100% precise and accurate in terms of both numbers and locations. In my career to this point, I and my friends and clients have caught 11 fish which measured at least 31 inches and weighed at least 10 pounds, or were less than 31 inches but weighed at least 10 pounds. Over time, we've caught a considerably larger number of other trout which measured at least 30 inches and/or which weighed more than 9 pounds; the larger number elevates the utility of the data.

Analyzing the facts related to the locations where the 11 giant trout came to hand helps clarify how considering raw numbers rather than percentages could lead an angler to draw conclusions which hamper the potential productivity of their efforts, rather than enhancing them. These are the basic facts: one of the fish came from Alazan Bay, two from the Tide Gauge Bar (one on the shoreline north of it, one from the bar itself), two from Cathead (one at its west end, one near its east end), four from the North Badlands, one from Yarbrough Flats, and one from the King Ranch Shoreline. Key word from the previous statement is basic. Consideration of the places in such generic terms doesn't really allow for ranking them in any legitimate order with regard to their potential for producing trout of the specified dimensions.

When looking at the details related to the catching, one must make every effort to equalize the scale of the included sites in order to draw accurate conclusions about the relative potential productivity of each of the places. Alazan Bay is an entire body of water, while the other locations are parts of bodies of water. The King Ranch Shoreline is many miles long, so though it's a part of the ULM, thinking of it as a place the same way one would think of Cathead as a place doesn't make much sense. In order to glean anything meaningful related to the relative potential for these places, one must define them in similar dimensions. Doing so leads to the next step in the process―moving beyond the raw numbers and generating percentages.

At first glance, the fact I and my partners caught 6 of the 11 fish in the Badlands/Cathead area would seem to indicate the area offers better potential than all other similarly sized ones on the map in terms of ability to produce the desired fish. 54% of the fish came from those two areas. If I and my partners spent 54% of our fishing time or less in those areas, we can correctly deduce the chances of catching the desired fish in the Badlands or at Cathead is higher than elsewhere on the map. Using that basic method of analysis, I would concur with such a statement. But, reducing the scope of each of the places where the fish were caught changes my opinion.

For instance, I and my people managed to land just one of the desired fish at the west end of Cathead. So, 9% of the fish came from that place, or spot. Defining the spot in Alazan which produced one fish, or the drain behind the Tide Gauge Bar, or the short stretch of shoreline on the King Ranch using the same dimensions as the west end of Cathead leads to a different conclusion. I and my partners spent far more time fishing at the west end of Cathead than at any of these other spots, all of which produced at the same 9% rate.

This illuminates a main point. Thinking of productivity in terms of percentages and considering spots or sites of equal dimensions allows for a more meaningful analysis of facts than simply thinking about how many fish each spot has produced, as a raw number. The best way to compare the relative productivity of spots involves not only considering places of similar size and scale, also the catch-rates at the spots with favorable prevailing conditions. An angler with accurate data of this kind can generate a much more useful percentage outcome value than one who has tried spots without thinking about whether fishing them makes good sense, given the prevailing conditions.

Any decent coastal angler recognizes how changing conditions affect the potential productivity of spots throughout a body of water. These conditions include tidal movements, tide levels, wind speed and direction, the temperature of the air and water, the level of turbidity in the water and the presence of food for the targeted fish. Making an effort in a place under unfavorable conditions diminishes its perceived long-term potential in a misleading way. The most useful statistic related to the potential productivity for a place involves a calculation which divides the total number of fish produced by the number of visits made to the place. (See imbedded image, titled Calculating Production Average).

Generating a useful Production Average number for a spot involves some key considerations, the first of which relates to the raw number of fish produced. If the angler crunching the numbers counts only the fish they personally caught, then the number of visits to the place needs no modification. If, however, the angler counts all fish caught by anyone in the group, the number of visits must be multiplied by the average number of anglers making the visits. A second consideration involves other aspects of a visit; an angler should only count visits made to the place with conditions conducive to catching in play, and those which last for at least an hour. Visits which involve stopping for a few minutes at a place and making a few casts should not count in this calculation. Similar truths apply when attempting to determine the relative potential for various types of lures to produce desired fish.

In order for an angler to justify throwing a particular lure (or even type of lure) 75% of the time, the angler would have to catch at least 75% of their desired fish on the lure. Any lower percentage would mean the angler wasted some of their time throwing the lure. More than likely, anglers who have tunnel vision for particular types of lures (mostly either soft plastics or topwaters, in my experience) don't realize they're throwing those lures for long spans of time when they aren't at the top of the list of best offerings for the moment. Some likely don't even think about how often they throw their favored lure in ways which would allow them to recognize how the choice limits their productivity.

If anglers afflicted by tunnel vision fall into the trap of thinking only about the raw number of desired fish each type of lure they've used has produced, rather than calculating the percentage of desired fish produced in comparison to the percentage of time they use each lure, they'll draw conclusions which hamper their potential for productivity. If a person who throws a topwater 85% of the time has caught 20 trout measuring 27 inches or more on a floating plug, and 10 on soft plastics, the numbers suggest the angler's fidelity to topwaters is hampering productivity, because 67% is less than 85%. Focusing on the fact 20 is twice as much as 10 leads to a misleading conclusion in this case.

In order to accurately assess the potential productivity inherent to lures and places, one should optimally consider percentages rather than raw numbers, basing those considerations on thoughtful timing, either of the visits to the spots or the choice to deploy the lures, given the prevailing conditions. More data leads to more meaningful conclusions. In the end, for me, reducing the quality mark to 30 inches and 9 pounds leads to more useful conclusions than drawing the line at 31 and 10, because of the increase in sample size. I suspect novice anglers tend to place too much value on data of too small a sample size and think too much about raw numbers, rather than calculating accurate percentages and using them to draw logical conclusions about where and how to target fish.