I searched
Alford baptisms 1812
then clicked "Images"
If that hadn't worked, I would have tried 1811.
If a page is indexed 1809-1812 then searching 1810 or 1811 won't find it. 
I know pamthomas has other ways of finding things. 
pamthomas does things the 'long way' to make use of her maths skills.

1. Checks for the correct parish name by scrolling to the end of the 'how to search parish registers' download in the help section.
2. Enters the parish name followed by PAR 1 in the 'with the exact phrase' box on the advanced search page.
3. Scrolls down results page to find correct register (e.g. if I want baptisms 1820-1840, ain't no use selecting
burials 1863-1911.

4. Checks 'years covered' to 'number of images', and calculates either images per year or years per image, depending on which number is the larger.
5. Then calculates which image number is probably the one I want.
e.g. I want a baptism in about 1827. The register covers 1813-1837, and there are 48 images. 48 images covering 24 years equals (on average) 2 images per year.
Therefore a baptism in 1827 is likely to be 14 (number of years between 1813 and 1827) times 2 (average number of images per year) equals 28.
6. Checks years covered on image 28, and then goes backwards or forwards as necessary.
It gets slighter more complicated when you get, say, two and a half images per year and the register covers, say, 1813-1870.
That's when you have to be
really good at maths.
