Sure...here's the explanation of why a 1 shows up as MATCH(1 in that formula.

The first argument of the MATCH funtion is the lookup_value. So why is it, you may be wondering, that a "1" is being looked up when clearly the column headers, row headers, and numbers in the table do not equal 1.

First, keep in mind this is an array formula. In the example I posted on that link, the array formula is

=INDEX(A1:N19,MATCH(1,(A1:A19=A24)*(B1:B19=B24),0),MATCH(C24,$A$1:$N$1,0))

Aslo keep in mind you are matching items in separate sets of array elements. Does element #1 of set 1 equal element #1 of set 2? The array formula is determining that behind the scenes and returns (as you'll see) either a 0 (meaning FALSE, or No) or a 1 (meaning TRUE, or Yes).

Suppose you reproduce the worksheet based on that that link example. Suppose further you select the cell containing that formula, which is cell A27.

Now, if you click into the formula bar, carefully select this portion of the formula...

(A1:A19=A24)*(B1:B19=B24)

...and press the F9 key. Don't hit Enter, just F9.

You will see this in the formula bar that is selected:

{0;0;0;0;0;0;0;1;0;0;0;0;0;0;0;0;0;0;0}

and this as the larger formula in the formula bar at that moment:

=INDEX(A1:N19,MATCH(1,{0;0;0;0;0;0;0;1;0;0;0;0;0;0;0;0;0;0;0},0),MATCH(C24,$A$1:$N$1,0))

Notice there is one "1" in the array of returned calculated elements of

{0;0;0;0;0;0;0;1;0;0;0;0;0;0;0;0;0;0;0}

and it happens to be in position (also known as index) #8. That is, the eighth index position in that array is a 1.

Notice further that the table in the example starts in row 1 and the formula includes row 1 in the entire table range arguments, for example

(A**1**:A19=A24)*(B**1**:B19=B24)

So, eyeball the eighth row down in the table, which coincidentally is the same as row 8 (index is a relative reference to the table range, not necessarily to the row number) and you will see that the criteria values in cells A24 ("Postage") and B24 ("2010") are the same as the values in cells A8 and B8 respectively. So, a TRUE match was found and the array properly returned a "1" for that element. And because a 1 was the lookup value, representing a TRUE match for the 1 that was found in what turned out to be the eighth element position of the array calculation per the F9 action described above, you know row 8 is the row of interest.

Again, index is relative. For example, if the table had started in row 4, the eighth element would have been grid row 11.

If you actually go through this exercise, remember to hit the Esc key to exit the calc method of F9, rather than hitting enter to commit the hard entry to the formula in the formula bar.